After spending the best part of an hour retrieving seeds, stopping the other side planting seeds, running back to guard base and in between having a nice little ground war I’ve concluded that the mode needs to be refined; I think maybe a lockout system to give one side a definitive chance to retain all five seeds and/or reduce the amount reuired is key.
Another concern is that as the length of the game proceeded, the opposition grew more and more toxic in terms of teabagging, griefing etc.