You can move "up" and "down" rules among the listing but I don't think this will have any effect on the issue you're having.
I tested it out as the same way you did:
Rule #1: Move email to a folder coming from person X.
Rule #2: Delete email with subject: Summer
I sent an email to myself so I thought the mail would be moved before deleted or even better, won't be deleted...
The email has been deleted automatically...
You can set exceptions as the end of the rules properties. By example: You can set that rule so when you receive an email with Summer as subject, sent from "Boss" this mail won't be deleted.
Hope this answers your question.