This will not be popular with HTC because of the major map re work required.............however.
Consider three LW arenas each as follows
Bishops v Rooks (red arena)
Bishops v Nights (white arena)
Rooks v Nights (blue arena)
The arenas are interactive. ie to win/lose the war a side must be reduced to its minimum in both of its arenas.(eg 5 fields across two arenas)
Look upon each arena as a "front"
the "status" of all arenas can be seen from a tower in any arena.
each arena has its max limit as now.
subject to the total cap limits, players can move between arenas.
subject to the country balance limits, players can move between arenas.
subject to country balance limts, players can move between countries.
players in smaller arenas enjoy greater perk multipliers.
perk mulitipliers and eny benefits/penalties still in place per arena to influence balance.
There is no communication between arenas.
Removed from gameplay is three way combat zones:(
Arena communities are smaller
Land grab objectives are unchanged everyone is still fighting for the same side
Side balancing influences remain and are added to in order to balance arena numbers.
Even if a side had massive numbers the system would force those numbers to be split more evenly across two arenas.
edit.
There maybe a way that this can be done on one map.
Consider the typical big map split into 3 countries ...... from the start point the fields are designated as red/white/blue fields.
Players can only spawn from a blue field if they are in a blue arena.
They can only communicate with blue arena players.
They can see and fight with non blue players at the "joins".
They can bomb and capture non blue fields and facilities..but they cannot use them for the advance of their country into red/white arenas because they cannot spawn from them.
Obviuosly maps with a large central void are better for this.