OK I get it. I'm not going to argue the presence of the caps here, but what I will do is mention this.
It's no secret that the Orange Arena is almost always more popular than the Blue Arena. The question is: Why is this? Surely enough time has passed since there was only one arena years ago to where both arenas should typically be 'equal'. So why does this bias exist?
I personally feel a big reason for this is because the Orange Arena is listed first! People tend to associate 'higher on the list' with better... more popular... etc.. etc.
How about make it so that the late war arenas are random as to where they appear on the list. It could be orange on top.. or blue on top.. or if the game ever gets popular enough we can introduce a Fuchsia colored arena as well and it might happen to be on top. This way when people who don't care about which arena click on the first on the list, it is more evenly populated. The people who are dedicated to a specific arena will take the time to click on whichever one they want, and while this won't fix everything I feel that it will definitely help.
I also think a 'squad invite' should be available so if an arena is full, someone's squad can invite them in anyway (with the necessary amount of votes of course... perhaps 3 or 4)... but maybe that's asking too much!
Haha thanks for listening!