User blog comment:Kaloneous/Mass Effect 3 Ending DLC Denied and PAX/@comment-4118072-20120318222722/@comment-132.3.49.68-20120318232954

BioWare could say that Thanix Cannons could do considerable damage to Reaper ships as the Thanix technology was developed from salvaged parts of Sovereign's main gun, effectively using modified versions of the Reapers own weaponry against them. Also codex entries in ME3 talk about the Turian fleet taking on a Reaper fleet at the Turian relay and, using quick maneuvering and concentrated fire, were able to destroy/incapacitate several Reaper ships. This points out that one fleet is actually more than capable of taking on a single Reaper. So yeah, a final battle against Harbringer with you calling in orbital strikes is feasible. Especially since codex entries put Harbringer as the leader of the Reaper forces attacking Earth; standard military doctrine is to prioritize enemy leadership when at all possible.