But from the question, it sounds as if the Buyer's realtor is also representing other Buyer's for a back-up offer. I'd be very queasy about that as an agent. If it's another agent in the same office, shrug...it happens. But I would prefer to be representing only one client but wholeheartedly.
It felt awkward a few months back when I had two clients interested in the same house. Only wrote an offer but didn't get, losing out in multiple offers. I would have referred the second Buyer to another agent had they wanted to write an offer as well.