Your bugs line up (Lead through spot 5) plays a huge difference, especially with mass assist attacks. GBA lead with Sun (2), Soldier (3), Spy (4) and Poggle (5) Mass assist attacks utilizing only the assisting attackers basic, this lineup leaves the target without buffs, debuffed and vulnerable for next attack. Enemy drops like flies and can pretty much be accomplished on Auto with select targeting. (Clone Medics die first)
I've used this tactic since my first attempt (only had GBA at G12) on Wat and have had 100% success.
Gear level on GBA will directly reflect on Brute and I have, since beginning DS Geo TB, put R6 on GBA and R5 on Spy. All other bugs are at G12+5. They destroy the Wat and Acklay missions.