Kelton, it sounds like there's something way more than normal going on with your larger plants. The difference between small versus larger plants is a function of transplant shock (minimal for plants these sizes, if plants are in good shape and handled correctly) and root system adaptation.

I'd bet there was either a drainage issue with your larger plants (possibly having to do with the extraordinary amount of rain we've had lately) or maybe even some disease issue. Something that comes to mind, but may or may not be related to the problem, is the difference between the potting soil and the surrounding soil. If the area where the hollies are planted is not well draining, the difference between the surrounding soil and the potting soil can magnify the wet/dry conditions in the rootball. When it's raining, the bark-y potting soil, surrounded by poor-draining soil, can hold water like a bathtub. When the area dries out, the finer particle surrounding soil can actually suck the water out of the bark-y (larger particle) soil, and cause premature drying. This frequently happens to some degree when pot-grown plants when planted out, but it could be happening to a greater degree in this case (maybe).

The larger plants were clearly in those pots for a long time... they had all kinds of hardwood prunes to keep them to size, too.

I wrestle'd with the root balls to break them up just a bit.

They were planted in native soil.

I'm guessing the shock of all my wrestling may have put stress on the few that did a leaf drop.

All of them are showing new growth, now. Unfortunately, the previous pruning makes the branches un-naturally crooked...it will take time for the things to flesh out.

The small (happier) hollies also have the advantage of allowing me to shape them in the direction I like (a nice standard, for example).

The small ones that were re-potted into larger pots are positively explosive, though. I used 50%native soil in those pots, too (although I don't know if I'm supposed to do that).