Thank you both for your replies.
I do know about comb-filtering (to a certain extent) after having read several papers and hundreds of posts on the subject.
It doesn't seem to be as clear cut as I thought it'd be, hence my interest in using these 3 speakers, be it at a certain distance/angle from each other to alleviate possible comb-filtering.
What I'm trying to ascertain is whether an optimum combination of both distance and angles between the speakers exists, that would bring a significant improvement to my center channel (dispersion, clarity, power handling...).