BillyBob,
I have a cat named BillyBob, by the way, my wife named him Billy Bob Tailed Thornton, for obvious reasons.
I don't disagree with anything you said, but my point was that as long as he stay with the same manufacturer, which he is obviously doing, that he should worry too much about timbre in a home theater system. What you say is true, I wouldn't intentionally mismatch my front three speakers, say from different manufacturers, any more than I would use two different speakers in a stereo only setup. I think sometimes people new to a hobby or interest get caught up in the latest buzzwords that get thrown around and give assign those things more importance than they sometimes deserve. He is, as you say, going to have to "do the best he can", because that's all he can do. So I was just trying ease his concerns about timbre as a result.