Sorry if everyone knows this already, but I've only just noticed it...

I'm sick and tired of having unprotected arty units come on one at a time as reinforcements (ie, if you've got a fullish stack and some units rout etc.). Well, you can change the order your reinforcements come on by dragging the unit cards around on the pre-battle screen.

Again, sorry if this is blindingly obvious, but it's taken me this long to spot so there may be others in the same boat...