Yeha, would have to change the AI a bit to add priority to their attacks. Heavy attacks first, then secondary, then weak.
I doubt it would be necessary. In fact, I believe the problem was a bit overblown. I used to run mercs with a buddy who played a /kin corruptor and never had much in the way of problems. It's possible that it was a bigger deal with other primaries though. Plus, even if they don't perfectly use the improved cooldowns, it would still almost certainly be a buff.
I'll admit, I am no code expert, but this seems like it would be a very easy thing to test.