I personally prefer notches that are 4 pieces. The one piece side plate design is the most elegant for both visual and strenth reasons. BUT... Every nothch listed above will be way overkill for a mini or a fullsize that wouldn't be used for towing. I would always overkill a tow pig.
What do you suggest? One truck is a 53 GMC and the other is a 86 C-10 and the C10 will be towing sometimes. Both will be made to lay frame. When you say overkill are you speaking of the thickness of the plate?
If you build the notches for either truck out of that 1/4" thick plate you will be fine. Towing or not, bag in front or behind the axle, 1/4" plate is plenty.