How do I actually layer these grants without losing one?

The practical way to layer grants is to get everything mapped out with your lender before you submit any single application, since the order you apply in can disqualify you from a program that requires being first. Ask each program administrator directly whether their funds can be combined with another source, rather than assuming based on general program descriptions online. Keeping documentation organized for every source also prevents a delay at closing when the closing attorney needs to verify each one. Joel Boss can point you to lenders who specialize in exactly this kind of stacking.