The current map is the one with pre-set magic sites.
In my opinion, the main concern would be balance, especially the 60% discount on blood magic site, if a blood nation gets it.
I can play either with or without the pre-set sites, I think the balance problems can be solved via diplomacy (but I may be wrong)
(BTW, I did check all sites when I saw that our map had pre-set sites, so I can list them with their effects, if we keep playing on this map version)