Tenacity up should mirror Potency up

Imho, the problem isn't so much tenacity up, or a cleanse. It's the fact that two toons can do BOTH of those, and in particular Rex applies Tenacity up after cleansing debuffs. Tenacity up by itself seems just fine. Yoda is considered underpowered, if anything, and he only grants tenacity up without cleansing first.

I guess you could argue from a principled point of view that tenacity is a worthless stat, and tenacity up giving you instant infinite tenacity just makes the stat even more worthless (why bother with it, right, when you can just run Rex, Chirrut or Yoda and give your whole team infinite tenacity).