I usually use my numpad keys to use abilities if I'm singlebox raiding (fury warrior hardly has need for clicking)
You could do the same, try not to have any ctrl or alt combination on those keys for the clones,
You might accidentally activate 'm.
Downside is that you'll have to grab your mouse if you need exact targeting,
tabbing till you have your target could work, but calculate the lag in if you're nuking with the clones.

I've been main assist for raiding for a short while and trust me, it's about the same
Even when I targeted a banished mob they'ld start nuking on it :s