Lesser/Greater Scaup hybrids

Auchenreoch Loch. I reckon there could be 3 birds. There's 2 with clean white flanks & 1 with dirty grey & also with a dirty grey/brown mantle. The 2 pictured are hanging out with what I thought was a Tufted & always a very close 3some. Due to the size difference, I think the o/a nicely chocolate brown female could well be a Lesser Scaup ♀. The 2nd clean white flanker is hanging out with a bigger tufty flock. All 3 males are identical otherwise, with principally green sheen but purply nearer the bill base & depending how the light catches the head. What do you think?