personally i dont think versa lok are up to the job they claim to be. look at all the 50-100 year old masonry walls that are tilted from excess forces on them.
if you do alot of versa lok, you know that you can get higher #s + shorter geogrid with 2a in the backfill zone versus soil, but this is dumb, how much does wet soil weigh vs dry soil? almost double. wet stone vs dry stone, almost no difference
so 2A gives you higher compaction #s = more friction force but when the soil behind it gets wet and doubles in weight, the stone does not. Personally i like a 12-24" soil layer on top of drainage column on the upper layer of grid to put some weight on it.