Amakiir wrote...
I'm uncomfortable with the idea that a few dozen quarians can hack the geth at this point. Quarians in their prime were unable to reverse the course the geth were on, despite likely having many times their current resources and dealing with a relatively primitive geth collective intellect.
Besides, if a few dozen quarians can hack the geth in such a manner then why can't the Reapers? Each Reaper is effectively billions of minds working in harmony and thinking at light speed. A single Reaper would be able to match years of quarian research on hacking the geth in a matter of seconds.
/speculation
Though, to be fair, the Reapers already figured out a way to hack the Geth far quicker than the Quarians. They went down the Heretic Virus path. How long it took the Reapers to develop that principal, however, is unknown, but we do know that Sovereign wasn't able to simply hack the Geth. I'll warn against over-estimating the Reapers to that regard.
The thing about Geth hacking is to understand why it doesn't work: the auto-fresher aspect that simply replaces the coding at short intervals. Geth actually aren't hard to hack: the issue is that the hacking doesn't last long because of the refresher overwriting hacked codes. Think of it as pushing back the tide: if you push back once, it still comes again soon enough.
Rather, the matter with compromising the Geth is circumventing that defense. The Heretic Virus was aimed at changing the very thought patterns of the Geth to change conclusions. Project Overlord was not even changing the Geth, but taking advantage of their natural state (religious inclinations).
Rael's research, and who knows how long it's been developed (dozens of years? Hundreds?) seems to be aimed at breaking the refreshing defense in the first place. Even the Reapers opted to go around, but if Rael's research succedes, then all the Geth become mitigated as a threat. Their primary advantage over all other forms of mech-forces is their resistance to any hacking: stop that, and they're just a group of LOKI mechs to be hacked over.