I have seen them together before and not noticed a problem.
FYI, (in case you weren't aware) foxfaces are rabbitfish and they can deliver a toxin from their dorsal spines, just like lionfish. Be careful, I seem to remember (could be wrong) that their venom is more nasty than the lionfishes. If you do get stung, emmerse the effected area in as hot a water as you can stand for as long as you can take it, repeat. Take some benadryl and make sure someone is with you to monitor your breathing and possibility of anaphylxis, if you are alone, go to the hospital.