I guess my hope would be that if the only arena available when numbers are low is the DA or a similar 'furball' small arena then it would compress the action and force fights.
You cant FORCE players to play a certain way. Many don't play this game to fight....unfortunately. And it may seem worst in the days to come. I think....and hope, more players will be coming over from WOT and will do nothing but tank.
However, what can be done to bring more fighting into the game is to adjust the rules for a "WIN". To capture a base, not only do you need to white flag the town, kill all ack guns, and get 10 troops into the maproom, add in thing that will move more player to defend, like ack guns come up faster if 5 defenders are in the air for 5 minutes.
Bombers only get full points/perks/damage if they RTB.... or atleast try to make it.
Defenders are far too few as to most people they have the most to lose. Be it points, perks, K/D, just plan dying, or what ever is their goal. Defenders get hammered. They are less organized as tend to get slaughtered more easily. Some thing needs to be done to make it more worth while to defend bases.
With more defenders you'll have more fights.
For the attackers, there needs to be a "carrot" to entice them to fight for their captures instead of "disappearing" when the going gets tough.
The point is you can't take away and arena, but you can make it so most players flock to a single one. You cant take away NOEs or "wack a mole" type grab and dash captures but you can make it more beneficial to fight for them. They still have to option to do the lame "avoid a fight" stuff, but they may instead choose to join a fight instead for the "extras" provided by the new rules.