Alright, plan B: hide the fleet behind (-on? What's the T/W of these ships?) Mars. They'll probably work their way in clearing each target along the way again, and even if they don't Mars will likely be a priority target. By the time they realize the fleet is there they'll be far inside the jump-line and quite possibly even in a vulnerable order. The Mars defenses can serve as an anvil while the fleet play the hammer and the 223 pick off any fleeing stragglers before they can escape. No messages out, the Tribute Fleet simply disappears.
If they're stronger than anticipated we write off Mars and do the same thing, but with Earth.
If they're stronger than anticipated we write off Mars and do the same thing, but with Earth.