By the way, wouldn't be more realistic if some units could actually enter provinces with low infra?
I mean, few areas are really unpassable for a barefeeted unit, especially if they're grouped with an ENG unit.
I would divide it in three levels:
Level 1 (infra 1-3): accessible only by feet units (INF, MTN, etc.) with ENG giving bonuses and other attached units (ART, AC, etc.) removing the possibility.
Level 2 (infra 4-6): accessible even by by mobile units (ARM, MEC, MOT) but only if they have ENG attached with them.
Level 3 (infra 7-10): accessible to everybody.
Anybody agrees?
No, the main reason for provinces not accesible is because the AI was not able to handle some situations in some places, so if you make what you states this means the AI will find again this problem, yes you can say that the real solution would be improving the AI but I can figure that this is hard enough for paradox wanting to do tricks like that