User blog comment:James12708/Reapers VS. Forerunners VS. Angels from Darksiders VS. Humanity from Halo VS. Council and humanity from Mass Effect VS. Imperium of Man/@comment-50.80.96.33-20130124014617/@comment-4967682-20130124035859

That wouldn't work either. The Reapers themselves are the only ones who can pull of the RKV tactic against other ships; reasons why detailed in codex/The Reaper War/Desperate Measures. The same entry says why crashing a bunch of ships into them wouldn't work either. Any tech the Flood reverse engineered from the organics they actually could infect would be useless.

You assume the Reapers would bother entering the environment when they can depopulate the entire galaxy in an hour by firing their 450 kiloton death guns at planets every five seconds.