I've had experiences with both.
This past season my son had a game and they needed a linesman. During the first half, the linesman was from the other team, the second half from my team. I know the guy on my team wasn't a ref, just someone who was willing to do it.
The game got contentious and the refs ended up changing to a 2 man team.
All my kids HS games use a 2 man system, one on each side of the field. It really gets the parents rilled up when a ref calls a foul on the opposite end of the field.
I guess the constant is that whatever the number of refs there are, we'll still disagree with their calls.