You make considerable points but my argument was on what we know: the threat the genophage poses. ME never even addresses just how useful a cured krogan could really be against the reapers. The emphasis was on getting the current krogan onto Palaven. Not on using their children as fodder. What you're saying is assumed. Are tank breeding facilities less feasible then traditional reproducing? We don't really know. My argument was on what we did know. It's the same argument I made when I defend holding the fleets back to focus on Sovereign. Posters will give lengthy explanations with strategies that are never mentioned in-game on how it's a "good idea" to divert resources to save the council. But I make such arguments on in-game facts.
But an argument of being reluctant to cure it because of what we know about the Krogan birth rate, solely to get Krogan support on Palaven is shortsighted, in my opinion. We don't know how effectively a cured Krogan population could rebound and help against the reapers - sure, but we DO know what the birth rate is and that can't be ignored, it must be considered and potential consequences or utility of it deduced. And we also know that it certainly couldn't hurt the war effort at all. Comparatively, one can deduce that sabotaging it just to get Krogan support to Palaven might indeed hurt the war effort, by eliminating a potential source of future troops. Anyone seriously thinking about strategy has to consider that.
But you raise good points, and the sabotage-or-cure decision was always one of the harder ones for me (without meta gaming) because every logical part of me wanted to sabotage it so damn bad. But I had to admit that their birth rate may be valuable in the long run. I consider it a sort of investment.
I also agree with you about holding the fleets back. I never save the council. Without metagaming, NOT focusing on Sovereign is single handedly the dumbest strategic choice that a Shepard can make throughout the entire trilogy. It makes literally no sense whatsoever to do that. So I let them die a thousand times over.