Sure when you are working with custom stats /skills/armors , 30 different classes for pvp.
You need to balance pvp with starting gear, pvp with max custom gear, and pvp for olympiad.
And then balance the pve too.( I can do this by self ofc).
Add limitation to the olympiad , custom balancing skills e.t.c.
So yes it will take 60~ hours I just added 20 more for any problem we face.
And yes all these servers that close within an hour maybe need 3 h for full balance and then they write 99% balanced server.