You're right it is missing that info in 7.7.3, but 7.5 still says that when a hex with more than one unit is attacked, all targeted units are attacked for the single AP expenditure.
Thank you for the quick response. I added the word targeted to your response as that's how it is written in 7.5. I obviously don't target my forces.
What a beautiful game. Congrats Uwe/Gunter! Thanks for your time at Gencon!