One way to reduce congestion in the ER is to take minor issues to an urgent care clinic. Most of them are open on weekends, so they are available in off hours.
Emergency room triage is tough to assess, sometimes. You can bet on the ambulance patients always getting first priority, usually because they are most apt to have life-threatening conditions.
I normally don't have a problem with ER triage methods. They have to take everyone who walks in, so they have to have a procedure for taking care of the sickest patients first.
I take comfort in knowing I'll be seen first if I ever go to the ER with something bad.