I think it's far more important to mentally or actually practice moving everyone and everything. Talk about who takes what/who. Make sure everyone understands how to do things. This is going to be sweaty work, but it doesn't also have to be snarky work, LOL.
In my family we carried carseat on the hip, without holding onto the straps because our manuals said to not do that. So that was a bit harder, and made child-wrangling a little harder. 22 months old...Ergo back carry (or mei tai, etc), backpack on front, carseat to the side on one hand. Stroller...hmm. If seats will fit safely in strollers, maybe roll them down the gate ramp. Ooh, have the 6 year old push one or both if they are umbrella strollers and you can rig them together if just for that time period.
Practice this, at the very least mentally, so it remains sweaty, but not actually difficult. No need to start off a flight with "I thought YOU were going to hang on to the littles" "but I thought YOU were" etc etc.