On the Tank/Inf co-ord question

[Grognard Gunny]

OK, following up on that reading of the rules...... the Leader can activate (his) stack, but the tank(s) cannot fire as part of that hexes' firepower???? If the tanks are activated (in that stack) are not the tanks in the next hex capable of being activated along with the Tank Leader in the original hex???? Or do the tanks fire their MGs as a unit.... but not part of the Infantry firing. 

Now I am really perplexed.

GG