I ran a modded server a few months back, and during stress testing we had 63 people playing at the same time without much instability. Its possible.

That's what it's currently made for.

Made for 10 people
To act as a tribe
both
???

is not that big when there is 5 biomes on development , ocean is almost empty an fng bored to sail ( really , just have a night mob ) , ice lands are empty , ash lands are empty and mist lands are empty but are the next to be filled

Well I hope So much more is added so I can have a RP future with it.
Like I dont know. Fenrir, Jormungandr, hell maybe even fighting Thor or Odin as a Final Test to see if your Worth.
But RP wise..... Oh boy the fun I can have with that....
start a tribe, Cause trouble in the Tribe, Be treated as a Out Cast, Fight the Gods to get respect, return to the tribe, and be come the new leader of the tribe. And thats just one of many ideas.

It is no MMO. 1 - 10 Player on one Server. This is Coop.

not looking to make it a MMO. Just something to make and act out a tribe or something and 10 people max? Map to huge for that. but heh...