Don't mind. All of them are different.
Politoed is a regular frog, Water. Seismitoad is Water/Ground, and uses sound-based attacks. Toxicroak is a Dark/Poison, Muay Thai Dart Frog. And Greninja is a Water/Dark, well, ninja.
I don't mind re-using animals when all of them are different types, and have a unique element to them.