Well, if you don't like house-rules, maybe, from now on, you guys overbuild your forces, and if you end up in a situation like that again, you can ask to swap certain units for a matching bv set that works in that situation. There are no hard rules for force building except the numbers and player agreement.
Or, if you don't go that route, and it comes up, ask if you can gain x amount of Bomb/Artillery strikes.
I too am curious which map this is. I think I know, but I'm not positive.
(What's funny to me is that the CF is tied to its infantry protection value. Do you realize that with the simple rule of CF/10 for armored units, you don't need to classify hardened/heavy/medium/light? Only when infantry are involved is the classification required.)
As for avoiding damage, don't forget that a Mech or tank actually causes damage to a building, coming and going. So, the PSR is to see if doing that damage it didn't get poked with a bone steel girder.