The reason you'll never see a senshi on pokémon.
Sailor Moon is confidant. She will win this fight with the monster today, but on new terms... Using pokeballs. What a genius idea! Just stick Tuxedo Mask and a few others in one of those and it really will be perfect timing. The fight progressed as usual. Then, "I choose you Tuxedo Mask!"
Tuxedo Mask then appeared. He looked uncertianly at Sailor Moon. Was he really supposed to fight the monster? It appeared, yes he did. Wham, smash, whomp! Sadly the only one recieving the blows was Tuxey dear... Oh my! "Tuxedo Mask come back!" Blindly reaching for one she pulled it out and said the name. "Shadow Warrior I choose... Wait a minute! Oops! That's a bad guy! Ahhhh!"
The battle took a bit longer but, happily, the senshi won. But as you can see, that is why no senshi will ever be on that show. Their tactics simply do not mix.