Simple idea to describe: Blitz game mode, 4v4 or so. Special arenas that take a long time to travel, you can have destroyable objects such as turrets and doors that require both Pro and Bot damage. Once destroyed, they cannot be re-built unlike turret nubs. The arena could be in 3 parts or so, with two jackbots along the way before the final part: the moneyball. Bots constantly stream from one end, the attackers, to the moneyball. Attackers must escort and destroy obstacles for them to pass through (note, these obstacles don't necessarily have to apply to pros like the Assault and the Assassin, but they won't get far without destroying the moneyball shield with bots). Defenders don't get bots, but already have a load of special turrets and breakable walls to slow or stop the bots, and can move right up to the attacker's front at the beginning. If possible, have multiple spawns to keep the attackers at the front. The defenders probably have to walk there. If spawns prove troublesome to work right, try jumpads or some kind of conveyer belt that speeds pros up (possibly bots to stop them getting assassinated too easily?) The winner is the team who won in the fastest time, gained the most money from turret and jackbot destruction in a tiebreak. This game mode would be played in two rounds unlike the other game modes for teams to swap. This gamemode could also indirectly improve crossfire by teaching newbies how to deal with defences and turrets.
Could work, but it would require some significant balance work. As the classes are right now, I think this mode would be utterly dominated by gunners, since they're so good at both siege and defense
Well it depends how people play Blitz I guess. Although Gunners could easily be taken down by a sniper if the map is built right, since even with lvl 3 deploy, I still get practically headshot, it just takes one extra shot since I wind up with red health after a single shot. I don't think the classes will have to be changed much if perhaps you use a smaller number so the teams can't go full highlander (1 of each) leaving some gaps in their line-up to exploit in a competitive game mode. And even then you could also make some respawn timer differences between teams to further balance it in favour of attack, but only slightly to allow some competition.