That I don’t know. Just saying that the pickup placement is going to depend on what kind of tone you want, not a hard and fast rule, so their answer was reasonable; and that emulating the MM’s HH isn’t necessarily any better than any other placement there. It will give you a tone, but not necessarily a better or worse one than other placements.
This is something you should talk to a luthier about. I know rough guidelines (closer to the neck on the neck will be deeper, rounder, and boomier; closer to the bridge on the bridge will be more trebly and growly, etc). But no idea about exacts.
You have the Gibson extremes with the pickups pushed almost all the way either way; the Fender middle ground, etc. But with the Sims I don’t know.
A solid guide might be to estimate from Mark’s, though that’s also a different bass. You could also ask him why he did his that way, which seems like a reasonable idea, and I bet he would reply.