In general I agree. I've always felt 12 personnel- if one of the TE has the ability to move around out into the slot, in the backfield, etc.- offers greater versatility.
But in the Rams current situation they do have wide receivers in Kupp, Nacua and Skowronek who can all block very well and do a lot of things from 11 personnel that 12 personnel concepts would want. Their versatility in that regard alleviates that need.
But overall, I would like to see Davis developed into a TE2 that can then be used more situationally. He has that sort of ability (as does Higbee).
