If a10.1 works fine with your server, use it. If it throws errors use the version a10.1.1. WorldGuard will be implemented at a later state but now it is still in beta and there are to many problems with 1.13 and WorldGuardAPI. On my side WorldGuard works fine (with version 6.2.2 instead of 7.0.0). But to be on the safe side I have disabled it again. If you use WorldGuard just disable the BuildersWands as they will ignore claims again.