First week 1-19, each week 10 levels more, with x2 and warmode xp most of the playerbase would reach it without problems, busy players too if not doing too much side content
Without cross the playerbase is about half, now add all the different class and leveling speeds of everyone, add lower healers to the mix in contrast to pve, you end up getting really long waiting times and empty zones, any pvp server under 8k should do caps to keep the average playerbase populated
Im waiting for Y'Shaarj to see if it lives up to Gurubashi constant massive pvp and events, kronos or turtle couldnt deliver that at all, low level 40v40 hillsbrand tug of war were peak private server content, caps would make every place a war zone, like it should, its a pvp server in world of WARcraft, ganking someone in the middle of nowhere in vanilla is not enough anymore
( Add /say /yell /whisp between factions, i want salt, i want drama )