speaker placement

Someone going 5.1 to 5.1.4 with a properly mixed system, in-wall KEF Ci4100QL-THX up front, a Q250c centre, Polk OWM3s on surround duty, an RSL 10S sub, all pulled together with Dirac on an RZ-30, and the question is whether the four heights have to match any of it. Short answer: no, and it is...