One thing to keep in mind about this question is that there are several types of Johtonian traditional dances that encompass a pretty large spectrum of purposes, traditions, and tones. While one might assume that “slower” would narrow down the field a bit, in truth, what’s more important to traditional dance is the intent, rather than the reputation of the pokémon involved; it’s possible, for example, to teach a scizor, a pokémon known for its speed, a slower dance if that’s necessary.
Just about the only true, consistent rule among all Johtonian dances is that the pokémon involved must have been obtainable among the entertainment and religious classes during our feudal era. That of course doesn’t restrict dancers to just pokémon listed in the Johto Regional Dex; rather, it restricts them to what was actually either native or easily imported at the time. (Eevee had been a common domestic pokémon since recorded history. The going theory is that they arrived here with merchants back when we traded with China, before our isolationist period.) Well, that and the pokémon must fit and dance on a stage in the first place, which means gyarados and members of the onix line are right out, as are some of the less nimble pokémon, such as forretress and meganium. Chikorita and bayleef are still fine, however.
With that lengthy preamble in mind, I’ll just quickly say that practically every pokémon has been used within the entertainment classes—that is, within the Jouto kabuki and Noh theaters. Of the two, Jouto Noh tended (and still tends) to employ more humanoid pokémon such as jynx, as the dance style of Noh theater requires participants to move in very precise, often synchronized fashions. Jouto kabuki, by contrast, is a little less rigid in nature (not saying that Noh is unenjoyable to watch, of course), and as such, there’s more creative freedom when it comes to choreography.
There is, of course, a third general type of dance for entertainment purposes—the Jouto buyo—which differs from the above in that whereas Noh and kabuki use dance to tell a story, the point of Jouto buyo is entertainment derived from the dance itself. (To give you a better idea of what this is, it’s often the form of dance foreigners associate with our form of geisha. Kimono girls, when not participating in ritualistic dance, often perform this as well.) Nonetheless, there is often a point or underlying meaning to each dance, usually associated with nature, and a dancer will often choose a pokémon that closely relates to such a meaning. For example, one of the most famous of these dances, the Sakura Dance, is often performed with bellossom, vileplume, or sunflora, due to their abilities to use Petal Dance and Petal Blizzard to enhance the performance while still keeping up with the dancer herself.
Outside the theater, though, dance takes on an entirely different and perhaps far more intimate meaning to Johtonian culture. You see, a lot of our art is derived from our belief system, and by extent, dance and music is often considered our means of communication with our gods, the spirits, the natural world, or some combination thereof. In other words, most Johtonian dances have meanings to them, and what message you wish to convey to the natural or spiritual worlds will often dictate which pokémon you can incorporate into your routine.
For example, the reason why the kimono girls of Ecruteak City, my mother included, relied on eevee and its evolutions is because those pokémon are closely tied with Ho-oh. It’s said that eevee can evolve into “a different color of the rainbow” (that is, a form that matches Ho-oh’s seven colors), so dances meant to communicate directly to Ho-oh are either done by eevee trainers or performed alongside eevee and its evolutions to evoke Ho-oh’s rainbow—and only by either of these. (There are other rules, of course. For example, men can’t perform the dance because it’s said men angered the gods enough to drive them to destroy Lugia’s roost and chase both birds from Ecruteak City, so if you’re male and you don’t have an eevee … you’ll have to be content with prayers at a shrine.)
The other gods, of course, are less strict about what you can and can’t use. For example, dances meant to honor or pray to Celebi can be performed with any pokémon that can normally be caught in Ilex Forest, although butterfree, beedrill, and golduck tend to be the most popular for their grace. Additionally, Celebi is said to be fond of “baby” pokémon, so some dancers employ pichu, smoochum, or togepi instead. As another example, dances dedicated to the legendary trio are often done with pokémon of matching elements to the specific legendary being honored (water-types such as starmie for Suicune, fire-types such as magmar for Entei, and electric-types such as ampharos for Raikou—with those three being particularly popular), and Lugia is often honored with dances that incorporate flying-type pokémon’s wind-based techniques (with many dancers choosing noctowl or xatu as partners).
Our festivals, too, often involve pokémon dancers that are closely linked to the dance’s purpose. Take our agricultural festivals, for example. (That is, take any one of them. Many Johtonian cities have more than one, with the exception being the coastal cities of Goldenrod, Cianwood, and Olivine, all of which were originally merchant or fishing settlements closely tied to seafaring festivals.) The agricultural festivals were often designed to either pray for rain and fertile grounds or give thanks for bountiful harvest thanks to these two things, so dances often called for either water- or ground-type pokémon—often both. As such, members of the wooper line are often vital to the more agricultural cities of Johto. Some towns also use grass-types, such as and especially bellossom and bellsprout, to encourage healthy crops. Poison-types are absolutely never used (with the exception of bellsprout, of course)—even if they’re partially grass-types—nor are fire-types, as using either is said to curse the crop to either never grow or to grow withered and inedible.
On the other hand, fishing and seafaring dances (as you would see in Cianwood, for example) may employ flying-type pokémon (such as noctowl again) to pray for good winds, water-type pokémon (usually golduck or starmie) for smooth sailing and bountiful seas, or simply normal-types (such as meowth) for luck. It’s taboo in those cases to use ground-, grass-, or rock-type pokémon, as these are thought to instill bad luck on a village’s fleet (because using these pokémon is asking for a ship to be “sent to the earth”—or, in other words, to sink).
With both types of dances, fighting- and psychic-types are often also employed to represent either humans (the fighting-types) or Lugia and Celebi (the psychics). Fairy-types are rarely if ever used because it’s said their fairy magic is volatile and unpredictable and thus could interfere with the meaning of the dance. They are used, however, in winter festivals, festivals to honor children, or festivals that are, in general, meant to celebrate life or bless a village with good luck. (Thus, they’re especially popular during new year festivals. Togepi and clefairy especially so, due to their supposed abilities to grant happiness upon those who see or care for them.)
Otherwise, many of the other festivals employ a vast array of different pokémon. Ice-types such as jynx and sneasel for winter dances (although dark-types are never used during the new year festivals to avoid inviting bad luck or evil spirits to a settlement), electric-types for summer dances, and so on and so forth. Just about the only type that’s universally considered to be taboo to use is the ghost-type, as these are only to be used for funerals and in festivals dedicated to the dead (because dancing with ghost-types traditionally represents dancing with actual spirits). It should be noted, of course, that for us, this isn’t exactly a somber event; rather, honoring our ancestors or the spirits of the dead in general is considered to be a celebration due to our culture’s emphasis on celebrating the good things done in life and the meaning of life itself. Thus, these dances can be a bit more colorful than Westerners may imagine, and the pokémon themselves tend to feel honored to participate.
So in short, it really depends on which dance you’re referring to or what you need to convey through dance. For the most part, pretty much anything that’s small enough to fit on stage and nimble enough to keep up with a dancer is fair game.
The Pokédex According to Bill 