If you wanna get pedantic the Feds didn't build battleships at all until the Defiant, because of Starfleet's silly "we're not a military" stance.
the defiant is not a battleship, its a corvette. a battleship is a size based designation, it basically means the biggest, and most likely, the most powerful class of ship. the defiant is a tiny escort, smaller then frigates like the miranda or saber, the size based classification below that is corvette.
the ambassador should get the exact stats the negvar has, 3 tac consoles, the engineering ensign, 9 turn rate, all but mounting duel cannons. and the galaxy R should get a different station setup, its long overdue to not be a complete pos.