Tbh also people just shouldn't be using them until targets are acquired anyways. Very few fights come up off the top of my head until thaz where this is a huge issue, and at least two I can think of ms pets shouldn't really be used anyways. The rest of the fights I'm thinking of, including thaz, either have the aforementioned ms pets are a bad idea in the first place, or have fairly simple methods to alleviate this. Even if it's all about picking up adds for cc or whatever. For example, these adds generally go towards people. Not away. Just slide on over to the back, pop em, and voila, problem solved. Sounds like your mages are just not doing that for whatever reason.
I got a few complaints at first yeah. Like oh here goes the fucking pets again, Oh it targets with f8 sadfase, I keep clicking it to heal etc. After modifying their usage a bit more strategically, I didn't, and I use them pretty much every other fight. Personally I only really use f8 in outdoor zones where I'm looking for the nearest thing to kill in a particular direction, and never click around to heal, as I've always considered a better strategy for that is simply to /tar *insert first few letters of name, usually no more than 3 here*. Takes about as much time as looking around for them. As for picking up adds for mez, yeah I can see how that might be a minor problem. But again. If your mages realize this, and take steps to avoid it where it may be a problem, you should not have any problems. Heck the only problem I've ever had with them is it is unpleasant to have a large seemingly disembodied cyclops ass in your face in highkeep.