Coming at this from having played Armada, where the Correlian Conflict introduced the possibility of 500 point games (on a 400 point system), 250 points in runewars feels about right for a larger game. As others have noted, at some point, you just have a line of units all across. I think at 250 you’ve got one medium stack with upgrades, one large stack with light upgrades, or two small stacks with light upgrades. I could have a lot of fun with that. I’m not sure I’d really want to see more.
what we could do is create a progressive tournament or progressive campaign where the size of armies varies and gradually increases.