Unit composition is just only a part of strategy. People who think strategy is unit composition simply don't understand the term. This is like saying Terran have 2 strategies which are mech and bio. -_-" Most people you are talking about may be people who simply don't get RTS game.Maybe, but most ppl wouldn't consider a 10s earlier stim to be a completelly new strategy. I am not saying it's not, but usually what ppl see are army comps that are viable to build and there are not that many in SC2. If you look at runes/summoners/item builds/counterpicking in MOBAs there is plenty of very varied strategical play just in that.