A good defensive stratagey would simply be to sit in the 5 point zone and drive side to side to prevent that sweet 20, and 10 point bonuses, as well as highest stack in thoes zones, which is 50 points + the 15 in highest stack meaning 65 points just from sitting in the 5 point zone
While this is a valid strategy, the defensive bot has to be very very careful to not get pushed into the 10 point zone. In accordance with NbN precedent (but contrary to Skyrise precedent), a defensive bot pushed into an opposing protected zone is at fault for entering the zone.
Wallbot effectiveness will decrease with the 48" horizontal expansion limits. However, the starting bar is only 48sqrt(2)", so a wallbot could be effective.