These are situations that seem to be outside the official (second edition) rules. Unless I'm missing something.
Suppose Russia is allowed attack Norway on the first turn, and does so with two fighters, three tanks (five units that hit with 1-3), and three infantry via Karelia, against 1 fighter, 1 tank, and 3 infantry. The five heavy units roll 1,1,2,3,4, an above average roll that scores four hits. Can the attack tell the infantry NOT to fire?
If the fifth unit is eliminated by infantry, Russia has to occupy Norway, possibly fatally weakening Karelia. Russia has now achieved its "strafing" objective (the German fighter should retreat, and the UK can occupy Norway on its turn.) So Russia would like to cap the hits at four, if allowed.
In the Pearl Harbor attack, Japan sends a battle fleet against the Hawaiian sea zone, and scores two hits on the first round. The US elects to take the carrier and fighter as casualties (so that the sub can withdraw).
If the carrier had survived, Japan can retreat its fleet to Wake Island, out of the Hawaiian dead zone. Can it do the same with a withdrawing sub? (The rules say that the battle is over, and the attacker must stand put, when the defender is DESTROYED. But the sub wasn't "destroyed.")
My theory is that the attacker relinquished his prerogative of "hot pursuit" of the sub and chose to withdraw after a short, one-round battle.