If your gonna complain about men, you have to complain about the rest. especially with the armored divisions.
the only way i could see your system working is also including ICs. You can only deploy a tank division in a territory over X. which makes sense, tanks did come out of factories.
But the tanks are delivered to the units training ground by rail. I have never heard of a unit who marches to the factory to recieve their tanks

.
On the other case, I agree completly with the problem of placing units in forward bases or annexed countries.
While it should be no problem of preventing the player of placing units in annexed countries, it becomes tricky with forward national bases (i.e. wake).
Some suggestions:
1. A simple solution would be to allow placement only in national provinces with manpower and then set all forward bases MP to zero
2. a bit more complicated solution would be to leave the MP as it is but having a special nat. prov. tag which reprecents a recruiting/training center. This would be an extra boolean (yes/no variable) for each province.
But there are still some problems, like what happens if a recruitmentcenter is overrun ect.