This BG isn't woking and i'm sure i don't need to remind you.

Seeing as it is 95% impossible to win on attack (without being given fail incentives that force both teams to drop arms and take turns), the game needs to revert to what it was unttil you redesign the actual BG scenario.

Towers: Defence rarely defend these becuase they pull the forces away away from the ring around the rosie game of capping flags.
Incentive to Defend: Attacking force gains a cap speed buff for each tower destroyed.

Tanks: After the towers are down these tanks become useless (except for blocking people vision). Give the Tanks some kind of utility such as a cap power of 5-10 players in the vicinity of a flag. Or a area Defence buff 5%-10% damage reduction to players within 30 yrds of the machine ( think APC in modern combat).

Finnaly something needs to be done about game of ring around the rosie that happens with each 3 flags. Maybe Increase the duration a flag takes to capture and give offense the ability to set up fortifications once a flag has been captured.

These are just simple ideas but i wish something would be done soon becuase its just a losing contest in its current state.