I`m against "wait" button. My reason is in most cases (at least - that was my experience with wait-function in tactical combat in HM&M series) that leads to "abuse" - I wait for other player (AI) units to be in range for a first strike. So I wait and AI waits and it will lead only to prolonged combat, but not to something useful (IMHO).

I agree that because of initial unit placement sometimes you have to skip turns with some of your units that are stuck behind the front line. But I think that solution is for better algorithm/calculation for initial unit placement (or some kind of formation-chooser before battle - there was several interesting proposition in other threads).

Maybe there is a better function: "swap places". Unit action, that consumes unit turn (maybe for compensation even apply some temporary initiative penalty -1 or -2) and swaps positions of unit A and unit B. So if unit A is in frontline and unit B is behind unit A - when unit B uses this action it will take place of unit A and unit A will take place of unit B. Off course the unit A and unit B must be adjacent to be able to swap places. That function will be useful not only for initial placement problems but also in other situations.