I think (guessing) the two of you might possibly be using different definitions of “better”/“worse”.

We’re not morally responsible for the fact some of us may have mental disorders (some like OCD which I have won’t leave us entirely), so stealing which we would be morally responsible for is worse than having a mental disorder.

However, having a mental disorder would be worse than stealing in terms of its consequences (we just can’t get rid of it no matter how much we try).

(At least I think it makes sense to accept both of your statements that way since I think having a large ego is morally bad independently of any consequences.)