A mode i can think of is called Defender. The objective would be to hold or defend a access point against upcoming forces. Look at it like Rush from battlefield. The point was to get the bomb then the defenders move back and attackers move up. No bombs but just the defense of a line or entrance to the castle. I had a thought of it starting as a assault like on a beach and the attackers have to attack a point and take it pushing the defenders back. All the way to the castle which could be the last defensive line. Have around 3 or 4 defence posts that the attackers have to take and it could be a 4v4 player or bots doesn't matter. I think the whole Viking ships on the beach and them running up to take positions would be pretty cool looking and fun to play.