But it IS a simplification in terms of game mechanics. And I recently LOST an argument where “game mechanics” won out over logic (see the topic Multinational Units on Attack).
Movement of each type occurs all at one time; all combat movement occurs at once, all non-combat movement occurs after that, THEN the place units phase, then collecct income. There is no non-combat movement of FIGs after unit placement, which the old rule REQUIRES. That is the “simplification.”