Having multiple accounts in different pools should not be an issue. Even dev is suggesting we do that as a failover option. Personally I have tried to mine with one worker but the difficulty gets too high and I get a lot of rejects. So I spread out my rigs on 3 different pools even though some of them are far away and still get a higher reject percentage but its far less than what it was.

At first when I had the workers pointed to one pool I had less than 0.6% rejects. Then when I joined them under one worker the rejects jumped to over 8%. Now I have about 0.8% rejects (and I had to lower intensity to achieve that) on average due to the higher latency. So I guess multiple accounts could be an advantage even to people whose main idea is not to cheat the system.