Great question. I definitely think that having a "joker" type receiving hybrid out of 13 personnel or even a 4TE grouping is a viable way to create a mismatch, especially in short yardage situations, like near the end zone or on a critical 4th down situation. McVay could use pre-snap shifts and motion to disguise it, so that the defense only has a second or so to recognize that the RB behind Stafford isn't really a RB or that the backfield is empty.
The media acts like what the Rams are doing is brand new, but I'm not sure this is really true. I think it is surprising that these formations and plays have returned, because they go against what had been the general trend in the NFL, and McVay and his staff deserve credit for being so creative, but it seems to me that they are very similar to what a few WC offensive coaches were doing circa 20 to 25 years ago, just not with the same frequency. If you go back to classic Andy Reid years with the Eagles, for example, they had some cool plays using unbalanced 3TE formations, or a single WR in a tight split. I wish someone would go back to the archives and dig up some old tape to compare side-by-side the differences and similarities. Are any of you old enough to have played old NFL video games from that era and remember those playbooks?
So, it seems to me that McVay probably didn't "invent" the concept per se, he somehow figured out how an "old trick" could be updated and modernized to work vs current NFL defenses and wasn't just an extinct dinosaur the game had passed by.
