It's a double edged sword. You are going to get people pissed either way. Because players have shown time and time again they will all crowd into specific servers, then bitch and moan the entire time about issues that come up from that(queues, in this case land space etc).
They will know exact numbers that can be on during HS, they could release more then enough servers during HS to allow all those founder players to spread out and have lots of land available on every server, but do you trust players to do that?
I can almost see 3-4 servers being completely filled in a week, maybe even HS, land claim wise. Not counting north where you need a castle first.
Imo one thing should think about doing, add a another column next to the population on the server selection screen that shows available land at that current time(split by faction) so they can at least say "Well it showed 95% of the land was taken, why did you go there anyway and then get upset you can't find a spot".