Hi Thomas,
The normal functionality of EXOR is it gets triggered if any one of the Predecessor events gets success, I mean to say if any one of the previous events gets finished/successful. If your requirement is like if you want to trigger EXOR step without any independent of predecessor events, only one event gets successful then you can go ahead and use EXOR fuctionality or else it won't fit your requirement if you want all the predecessor events should be successful.
Thanks,
Karan Lokesh