Btw, another thing which can be very frustrating: I choose some mechanized company with some APCs. Then in the beginning of turn 1 I notice that those APCs can't be loaded because my infantry are too "heavy" or just too big to fit into chosen APC... In the baddest cases, I can't even load my inf units into tanks too (maybe too "heavy" or too much men)
So, I must be very careful during unit choosing phase that I choose right APC type for all needed inf units.