Gang spar could get more popular if they do it so you get gang points for winning and only way how I can see spar community increasing is if they make different type of spars like melee only, bar boxing (kinda like eras), Pistols only, Specials only(like turkey gun and other holiday guns), Shotguns only,etc. And have the landscape make sense with the type of spar like for example a bar type area for boxing (if you knew your history it was popular in the Ol west)