Hi they look like they could be runner mixes with the breeds you said OR they could possibly be 2 rare khaki runners and a white runner. ( i doubt it) NOT show stock. My runners DONT stand up very much because they are from hatchery stock ...........
Oh, gosh. That white one is definitely a Pekin. He's HUGE! I have a fawn and white runner who is nowhere NEAR show quality, but he is still a lot longer and thinner than your white duck. I agree that the brown ones are probably Campbells.
Ya I have a fawn and white indian runner and she is very skinny and small, especially next to the khakis that are the same age. Pretty sure the white is pekin or pekin x
They actually look a bit like mallards for some reason. But im thinking khakis. They are not runners in any way. Unless they have a bit of mix in them.