by the way, it's interesting why there aren't specialists for Gremlins, Kents, Pokemon, and Fairies.

Because there are specialists for weak units. Trogols are bad on their own, that's why Shakti is needed. The same goes for the Dragon.
Ignat can't handle the situation; I don't know who relies on his special ability or even takes him as a starting unit.
Gretchin – I don't know, but I've heard good things about him.
As for a specialist for Pikemen or Kents, it's a huge imbalance (especially for Gremlins and Fairies).
By the way, the same can be said about Galtran. His existence is unjustified from a balance perspective, except maybe on M-maps.