I agree with the previous posts regarding Ninja. It needs to be buffed. I'm not sure how, but maybe giving unique actions to Smokescreen and Shadewalker would help.

And no, Stealthing with medals should not be removed in Feast. Taking Stealth away is like saying taking Fell Cleave away from WAR. It's part of the job. And plus having a stack of 10 medals and standing in enemy base is fun!