The reason is simple: it takes more manpower to revive a squad for Japanese than US
I actually do enjoy this gamemode, really. The only issue is that it does not work well in this kind of concept. I really like the pushing back to the zone kind of games, but this just hits different. I could imagine some hints into it, such as “Preparing for a push” and everybody has to be inbetween the captured and the advancing zone for a while. That way those who are about to attack could man up in a location and push together. And those who are defending cannot leave the defending zone.
The issue is with the players, not the gamemode.
Maybe those who lost a zone would not be able to push back until they succesfully take down the attackers.
In verdun, there is a getting ready time for pushing and defending. You have to counter the push to be able to push back.
Maybe, everytime you beat a push, or capture a zone you’d get a point. And the one with the most point wins.