@Krieghund:
The reasoning behind it is to not create an exception to the rule that land units cannot move in both combat and noncombat movement.
What would be the advantage in doing what you say? Wouldn’t you rather just move the tank into the contested territory in combat movement and add its firepower to the attack?
Usually yes. But when you are trading territories back and forth you usually avoid using all your available armor to prevent it from being destroyed in counterattacks. However, on that kind of exchange the combat results can give you unexpected outcomes like suffering zero/minimal losses and thus allowing for the attacking units to survive a counterattack. The advantage of allowing blitzing armor to move during non-combat would be to exploit those unexpected opportunities by further reinforcing the territory.
Example: UK has 3 inf and 1 armor on East Africa and the Germans took Egypt with 2 units remaining and control Belgian Congo. German Med fleet is still alive but there are no more German ground units on Africa other those on Egypt.
UK attacks Egypt with 3 inf + planes and blitzes with armor to Congo. It conquers Egypt without losses. It then moves the armor to Egypt to further defend it from a German amphibious assault.
The rule also only applies to armor in any case (and mech on the other editions) since no other land units can move 2 spaces. Mech can’t blitz so it doesn’t change anything for that unit.
IIRC, I think you can do it on Game Table Online (moving armor during both combat and non-combat, which then goes against the rule) but haven’t played there for a while.