Also, I don't think it's bad to have different wallets on multiple pool mining computers. I actually consider that much safer, because I think a greater chance could be someone stealing your funds from a computer you're not physically supervising all the time (cloud vps, friend's computer etc.), especially if the wallet is not encrypted. But for your scenario, first the small chance to revert to solo mining needs to happen, then probably even a smaller chance to solo find a block nowadays, then to not notice that you're not pool mining anymore (not see that you are not in the leaderboard, not check the mininginfo), and to never check the balance of the wallet. 
Maybe safer wasn't the right word. I just mean that if you have dozens of workers, it'd be a pain to go through each one in the event that the pool went down and check them for balances. It's the same in terms of private key safety either way, since the wallet on all your mining rigs would be encrypted (you can mine on a locked wallet just fine, only have to unlock to send).