Unwilling soldier leader 'Bot. Gives off a guardian vibe. I'd be tempted to make his alt mode one of the hover tanks found on this page
. For a name, try Ramrod
-- you know, the thing they used to load old cannons with.
Tac genius 'Con: Her alt mode should be the entirity of this
. The fact she can run two bodies semi-independently is part of why she's a tactical genius, and ties in to the movie back story of Arcee and her sisters (a 'con experimented on them as part of research into gestalt consciousness). She can only be killed by destroying both components of her alt-form. Call her Fire Fly.