It seems to me that any sensible division of land will greatly benefit Poly. This gives us opportunity for two diplomatic options. First, we can try to leverage this with our allies. In this scenario we'll let Poly to have the northern reaches and we also give CP more than their fair share of the land. We give the concessions in exchange for extended NAP and dibs in WPC and/or UCiv lands. So in short, we'll give up some short term gain but get much more land in the end. Only big drawback I see is that if we get majority of WPC & UCiv land, we may well face a 3 vs. 1 alliance, us being the solitary defender. The other diplomatic option is to sow seeds of discord between CP and Poly. AFAIK, that shouldn't be too difficult. We aim to hold the peace until we can annex UCiv lands and at least some of WPC lands, but the ultimate plan is to orchestrate CP + CFC joined attack on Poly. Good thing with this plan would be that at worst we'll face 2 vs 2 war if Poly can talk CivFr on their side. Anyway, I think that how this land division is handled will decide much of how the rest of the game will turn out. Though the land division itself is important, I think that how it will handled will be much more important. Thus, we should plan out our actions accordingly.