Hauling 5 half ton pick ups?

Yes it can be done but not stacked on the tail. The stingers that you saw stacking them on the tail were newer models with the truck package where part of the floor lifts up and over. Look at it from the side and you can see the roof of the bottom truck up higher than the bottom of the top trucks tires

 

I agree you need a trailer with the truck package. I've noticed that my high mount trailer that's a year old has started to sag on the upper decks. I believe this was caused by me hauling duallys and large pick up trucks. Too much stress and weight concentrated on one spot bouncing down the road

 

Saw a Ram 1500 over a mid size Jeep on a WM Stack custom & thinking that was 13'10 on the tail. Cannot imagine any other way of getting height down with 5 half tons w/o the truck package on a stinger. Does WM even offer that?

Is that a Miller or Cottrell with those issues?

 

It's a cottrell 5307. This past summer I hauled nothing but heavy duty trucks back from tx to the east coast. I never like how the trailer rode but the $ was good.

 

You should be able to with your Wally Mo.
#1 backed on far as possible, #2 pulled on far as possible, #3 far back as possible, and the 2 on the bottom pulled in far as possible.

Edit: Guess I misread I thought you already had a highmount.

 

@KANSAS TRANSIT has a pic of a highmount hauling 5 pickups. Maybe if you ask nice he will post it for you

 

I have not seen any mention of brand of P/U, wheel base or 2x2 vs. 4x4. You need pockets in the top rear and bottom rear. Just a few thoughts from an old car hauler.