Too much unknown at the moment. The dynamic is great though, one likes to box/punch from range and the other likes it a bit closer, so would be the stalker - a lot depends on Wilder's ability dissuade Joshua, which of course depends solely on Joshua's chin, I'm sure Wilder will find it. If we assume he has a reliable chin and the ability to fight effectively past 6 rounds then I think he beats Wilder to a standstill.

If not then he gets dropped and stopped.