Of the three bags, I like the last the best.
In a word "Solid" design.
With two straps and two tie downs the contents should stay in their place much better.
Nice work, something you might want to add to both sides.
I have a soft tackle bag that has a thin bungee cord sewn in on the top flap to create a loop. The loop attaches below over a button.
It's easy to attach especially out in the elements when it's windy and cold and fingers aren't as nimble.