My understanding is that Alligator was a Strat with a '57 body and '63 neck that Nash purchased in '70 at a pawn shop. If someone knows with certainty what pickups were in it in '70 when Nash acquired it, I'd like to know. If not, I don't think we know what pickups were in it when Nash gifted it to Jerry. Hence, people typically recommend not '57 pickups per se but modern pickups that sound like the ones from the Alligator recordings. Hence the recommendations you reference. Makes sense?
P.S. Here's a nice replica that was just down the road from me in Vienna, VA. I'd say must resist but apparently it's already sold! You could, if you want, ask Rusch which PUPs he used and why.
https://reverb.com/item/12229110-fender ... ca-natural