Buffs are a bit harder to tell, are the voices alike? Having the 2 lobes (belly flaps) and the short necks tell me both are goose.
My buff gander had a longer neck, and very shrill call.
I had purchased two American lavender ice as pairs, but the buffs.... One of them has a skinnier neck, but both sound the same and are about the same height. Their lobes (learned a new one today) is what threw me off because up until now I was sure these were a pair as well...