How important for surrounds to match fronts?

I'm getting aerial 10t's and an aerial center . Was thinking of klipsch ksp s-6 for surrounds since the aerial surrounds are out of reach
I have Aerial 7b and CC3b up front, Swans (much less expensive) in rear. I only use for movies not music in this set up. I think that having matched rears is less important for home theater, and also less important unless the speakers are quite exactly placed.
I've done it both ways and gotten good results both ways.

My listening room does double duty as a home recording studio. Since I use a pre-pro in my 2 channel rig, I'm able to quickly go surround if needed for an audio-video session. I have a small Marantz projector and use 3 of the 4 powered M-Audio monitors that are usually dedicated to the recording studio or connected to a remote Sonos zone as surrounds and a center. These M-Audio monitors are both less than optimal for surround duty (dispersion) and very different from my main speakers - usually Ohm 100s, sometimes MMGs, occasionally Verity P/Es. In all cases, the results are satisfying to me.

It may or may not make a difference. I had Focals as surrounds paired with my Revel fronts. There was a difference. One wasn't necessarily "better" than the other but it was different. When I replaced the Focals with Revel S30 surrounds, I only then appreciated what the full voice matching did for the surround experience. It was truly seamless.
I think that matching all speakers and timber matching is critical to the home theatre experience. I do think that when creating a home theatre like the movie experience the only way is with horn drivers-like the theaters have. The heart pounding dynamics are only created with a full horn loaded speaker. Plus subwoofers to add those last octaves. Take a look at Casta Acoustics and see what I am speaking of. Custom horns are simply amazing. You will not need another speaker.........
If you are focused on non matched speakers during a movie then turn it off.....its a bad movie. Speakers within reason will be fine.