The 7000 acre prov has 5000*15 = 75,000 k nw more dead land than the 2000 acre province. That's a lot of military you could have that he can't - so why not retal? If it is really bugging you, you can wreck their age surprisingly well just by being a jerk instead of rolling over.
"the army he left at home is still way out of the range of attackers in the Province B range"
- no, if he had that much more army than a typical province that size, he'd have way more NW too. If he got to the same NW size as you, you should have MORE military than him - 75k NW more military in fact. If you don't - that's your failing, not the games. 75% of my prov is military, so if I razed every single acre I had (and was 7000 acres) I'd be the NW size of a 5000 prov... still bottomfeeding down to 40%, which is pointless.
They also must have just spent a massive amount of resources to raze and rebuild all that land. Unless you are claiming they leave it unbuilt, and then they *really* are at a disadvantage.
Further - land based gains is awful and stupid. Whatever you think it might be solving, the new problems it causes are far worse. For one - forget *ever* warring unless you've spent at least 2 weeks straight pumping. Do you like sitting there gaining science all age long and never actually getting to fight? Cause I sure don't.
When "in range" is defined only by land, there is only ever one goal, to mindlessly cram as much stuff into your province as possible. Doesn't matter if it is fun, or intelligent, or anything - just keep shoving military into it until it will die if you don't keep aiding it every tick.
If you (people in general) really think the raze/rebuild for NW changing is that big a deal, maybe make barren acres worth 30 NW for the first hour or something like that. Does slightly odd things to chains with tornados or razes, but not really that big a deal for most people... while it'd add a lot to the nw of these top provs that are fiddling it that far. I don't think it is that big a deal, but if it is, at least target the solution at the actual problem instead of putting in one of the dumbest ideas utopia has ever suffered under. (I played some of those ages - it was as bad as "happiness", if not worse.)