Eric, you’re at a place where we’ve all been. I’m interested in the answer to Pat’s question as well. In one of your original posts you indicated you were planning for two 10-11” slabs with a 4” gap. That would put the outside leg width at 24-26”. So for argument sake, lets assume you were shooting for a 24” wide top.
You’ve either made the base width narrower than originally planned, or the slabs are wider than you originally planned.
If the latter, the obvious solution is to cut down the slabs a few inches. If the former, it’s a matter of how much less you ended up with. Miscalculations like these end up being “what can you live with”
If the base width ended up being 22”, or 20”, can you live with that?
I wouldn’t consider putting the tenons through the inside of the back slab. Just me. I’d either adjust the slab width, or redo the side stretchers to get to a overall width and inside gap you can live with.