After a bit the two toms started gobbling in unison and looking across the road.
Two more toms were working their way steadily towards them, also gobbling in unison.
I was hoping to see fireworks break out, but the birds just walked around each other before the two interlopers walked off.
Wikipidea cites a Nature study (Krakauer, 2005) showing the dominant male of two toms courting hens together fathered about 50% more young than males courting by themselves. I'm not sure how that works out for the other male, but given that they're usually (always?) brothers apparently the relationship means more of its genetic material gets passed on under the assumption it would have been completely unsuccessful on its own. Of course I'm pretty sure the turkey doesn't know that.