No, we don't.
Athereal is right, there's already lots of overlap among ATs, some more is fine. Corruptors, for example, are also not the best there is at any one thing, but they are good enough at a couple things that it works out. Scrappers are also not the best there is at any one thing, but they are good enough at a couple things that it works out.
What we are back to is "what does a Sentinel have to be able to do to be good enough?" and the simple answer is "a bit more".