I have always wet out 2 layers of glass at once. The bottom football shape with a large piece over the entire hull. It takes a bit more care in squeeging because it can trap some air but I've done 5 boats this way and got no air entrapment.

It sounds like in your question, you're thinking about wetting out a layer of glass and immediately putting another layer of glass on that. Don't! It's almost impossible to lay a piece of glass fabric on a wet glass epoxy layup. Everything sticks everywhere and although I've read of people doing it, it can turn in to total disaster unless you have a lot of experience. So, you have two choices. Both layers at once or subsequent layers within the window of epoxy adhesion. I use Raka no-blush. Make sure your system 3 is no-blush or use the manufacturers recommendation on the timing for a second coat.