I think its easy to have two nines of par 34 and par 36 so in that respect the 2 stroke difference will naturally represent c450 yards. I dont suppose people would really notice a 'natural' difference, whereas 2 nines equal in par and different in 450 yards is 50 yards per hole, that could be quite an inbalance.
eg. nine 1 360, 475, 180, 550, 430, 370, 160, 525, 400
eg. nine 2 310, 425, 130, 500, 380, 320, 110, 475, 350
nine1 is fairly tough and probably fairly typical of a modern resort type
nine2 many easy holes, group these nine together and I'd say its imbalanced.
nine 3 (par 34) 360, 475, 180, 350, 430, 370, 160, 275, 400
does not seem so bad