It is being assumed that the new domain will utilize 401x401 map size. Can we get clarification if a) 401x401 is the plan and b) up for negotiation if that is the case?
At least on the basis of the pre-server talk for "EN1", that might be a little... crowded. 801x801 is definitely too big but something in between might be just right. Much like Goldilocks and the bears porridge and beds. We've seen 501x501 used before on one of the specials, that might give us the necessary breathing room. I don't think anything bigger than 601x601 would be a good idea however.
The conditions under which the domains were moved to 401x401 are not the same as they were. Together there should be sufficient players to justify a larger map, though as some of us have argued even COM doesn't justify the 801x801 map size, so even together the combined domain won't. We are not the Middle Eastern domains with ~50,000 accounts each at any one time.