@swapgs "Handling it only at the "right" place also gets tricky..." - This is part of the reason I'm asking. My thinking is that with multiple guards you'll need multiple changes for thing to go wrong, so you may have to trace all of those during debugging.
Generally it may be true that finding the removal of the last guard will tell you what the problem is, but I'm not sure this is always this simple, and that by seeing the last guard only wouldn't mislead the fixer.
(Again, I'm not talking about security-critical checks here, in those cases defense-in-depth is clearly beneficial)