Grand Arena Strategy

If you're playing me, then no, it's actually a very good idea.

I'd say a qualified "yes" (it is a bad idea).

But without knowing your remaining roster, that is difficult to quantify.

Now, a zeta Finn resistance is always a bad idea to place defensively, because you are wasting a powerful zeta that allows the team to punch far above their weight class on offense, as the AI won't prioritize Exposed targets to keep the Turn Meter and damage output trains running.

A non-zeta Finn team is similarly not going to play to the teams specialty of capitalizing on damage output by striking an exposed target, but they still gain the other offense and defense bonuses from the leadership.

So the team will benefit as a whole, it just won't achieve the same damage output as if you played them manually (which isn't always optimal anyways, as hitting an exposed target might do more damage for that particular attack, but doesn't necessarily speed up your ability to beat the opposing squad by eliminating key characters).

That said, they will still perform better than a random selection of toons in the same defensive slot.

But only you can determine if your defense as a whole will benefit from the team on defense when comparing both your own and your opponent's rosters.

Hope that helps!

TL;DR for the post above:
Unless your opponent suck, zFinn will get destroyed on defense. So don't do that.

It is also a pretty awesome team om offense, so save it for that.

I can only agree with TVF, but only if you're against someone called Out Of Paprika