If she even has an option of asking for 20x reinforcements, we are all doomed anyway.
Indeed, my point is that the counter-strategy the GM proposed is ineffective; and that simply fortifying the relays would be far more effective. The point is not that fortifying the relays would be free, merely that it's the best solution they have, and the obvious solution for them to take. Sending entire fleets to chase around faster ships makes no sense when you actually have shokepoints you can reinforce and that the enemy must pass through.
I mean, the Rachni have 3 options :
1) Let us blow up their supply lines
2) Hunt the raiders down
3) Reinforce the relays through which we enter their systems.
They'd only pick option 1 if they were losing and literally could not afford to send forces, or if our raids were completely ineffective.
So, that leaves option 2 and 3.
Option 2 involves the creation of several major task forces that currently don't exist. It would require the diversion of nearly 100 cruisers, ~ 10dreadnoughts, and numerous frigates. All those would be operating in combat conditions, meaning they'd be patrolling, rapidly jumping in and out of FTL, and away from support infrastructure.
Option 3 involves reinforcing the already existing relay forces. They already have a supply line and support infrastructure, and all they'd be doing is floating near the relay. They'd suffer far logistical strain, and you'd need less of them.
In addition, since relays work both ways, Option 3 means that they'd also have an invasion force ready, as relay defense can be used as offense if needed.
And the fundamental Rachni problem I am seeing from WoQM is that they are horrifically overextended. Like, holy mother of supply lines.
I mean, if they have to mothball most of fleet due to upkeep costs, then "overtretched supply lines" does not even begin to cover it.
Yeah, doesn't real seem like the Empire that would go on to win against the combined forces of the enemy for several more decades. At this point, it feels like they'd collapse if exposed to a stiff breeze.
If they can't even afford to reinforce to stop active raiding on their own infrastructure, they're going to simply collapse.