Using your example above. Assume A&B are at 1k land(for easy calculation) and that A runs 40%homes as gogete recommends and B runs no homes.
A's pop cap would be 400*33 + 600*25=28200.
B's pop cap would be 1000*25 = 25000
Lets assume each lose about 200 land when attacking each other.
A's pop cap reduction= 40%*200*33+60%*200*25=5640
B's pop cap reduction= 200*25 = 5000
thus A would be overpop by 640 more then B.
You say that both will rebuild to tgs and forts so A will still be over pop by 640 while B has no overpop.
If both lose land till they reach 300(semi chain)
A's pop cap at 300 = 8460
A's overpop = 19740
B's pop cap at 300 = 7500
B's overpop = 17500
With 200 land incoming(moment land gets in)
A's overpop = 16740
B's overpop= 14500
After building TGs and forts
A's overpop= 14740
B;s overpop =12500
B would have to lose less pezzies, thieves,wizzes and specs to hit out as compared to A. Your bonuses are effectively nullified as you would still have to lose them in order to hit.
Even if you try to maintain your build of 40% homes, you would still be more heavily overpop then a province who run little to no homes. Also dont forget the high cost of redrafting,retraining all those lost units which would have been lesser if you run modifiers instead.