My first suggestion would be start with the point system. Should go 1 pt for capturing middle flag 2 pts for securing enemies vault. 1 pt for Defense team securing their own vault. First to 5 pts. See how that works. There is a lack of incentive to capturing the middle flag due to it being easier to turtle your own vault. If it was worth 1 point, which becomes equal to the defenders points, then the aggressors are always ahead technically speaking. Second, you guys should check into the ability for the defenders to secure their own vault versus being based on defending on time alone. And if they manage to secure their own vault, it reopens middle flag. It could take them 50% longer to fill up the bar than the Attackers but could actually create a much better Tug of War feeling than what you had currently. Oh also heavy ammo should be less frequent. Even in other modes in 4v4, it can create too much momentum and chaos. And then spawn points may need tweaked but this may actually be a map design issue to be honest. 1 Super can screw over a Defending team and leave little to no room for counterplay or escape. I used a Nova Warp against the Defending Enemy and literally had them stuck in spawn with no ability to react properly while my team captured the point.