Your argument is for a fullback, not a fifth running back.
We do NOT need a running back in goal line situations. We need a fullback. Belichick has apparently chosen to use Hochstein in that role instead of signing a fullback who would also be a blocker on the special teams units, as we have had for a couple of years in Evans. The backup gameday OT could also be candidate to be a goalline fullback.
You talk about needing the horror or using Faulk as an every down back in case of TWO injuries at running back. One of Taylor, Morris or Maroney would be the running back with TWO injuries. Perhaps that is the reason that we don't need BJGE. He would only be needed for major reps if there are THREE injuries at running back. And just BYW, I would be fine with a game or two with Faulk as the primary back. He has done well in that role in the past.
IMHO, BJGE's getting a roster spot depends on Belichick's patience with the continuing injuries to Morris.
While you are correct in many ways, there are a few things that you either mis-read, or I simply did not explain well enough.
I certainly realize the difference of a FB and a 5th RB on the roster, but I believe the gap lessens a bit this year with the departure of Evans, and the decision not to replace him with the prototype FB. Regardless, it's still going to take up 5 spots anyway, whether or not it's 4 RB/1FB or 5 RB.
I realize the versatility of a good backup (IMO) like Hochstien, not only on the line, but also as a lead blocker/FB a la Seymour and Vrabel in the past. This could certainly get the team through, or do in a pinch--but it's not the same as a regular FB obviously. My examples of BB using a 2 RB set, or the need of using 3rd down backs, goal line situation, etc was simply to state the importance of depth--especially in a RB by committee approach. With our somewhat aging backs, and the uncertainty (as I said, to be determined) so far of Maroney, coupled with the fact the Faulk is a great 3rd down back and shouldn't be used as an every down back, the need for depth is absolute.
When you said Faulk has worked in a pinch for a game or 2, I certainly agree, but you are figuring that it'd be short term, like in the past. Should the need arise for a longer term solution, there is no doubt that we'd be searching for another waiver wire pickup. So I'm not scared of the "horrors of using Faulk" as you state, but since he is such a vital cog in the offensive machine, I don't see BB risking him to injury for too long of a period as an every down back.
Basically my take (right or wrong) was this:
Faulk--#3rd down back
Maroney--??? whether it be bad blocking, bad luck, mental issues, the famous 'poor vision,' etc--the jury is still out somewhat. FWIW, I'm not bashing him, and I think he's a good RB, etc, but there's always a chance that he won't be a productive back in this system.
Taylor/Morris--both older, somewhat of an injury worry
So, that's why I figured 2 dinged up backs lead to BJGE, and not the 3 that you feel. You very well may be correct, I am just stating my reasoning. Like I said regardless, whether it's a FB or not, it still leads to 5 roster spots. This is a crucial year to develop a good running game, and we need better chipping, blitz pickups etc to help Brady return from a serious injury.
I have not seen much from Slater, who is a low rd pick anyway, so if this is the spot, then so be it. The ST this year will already take on a different look due to additions of other players, rule change, etc. I think there are other players who can replace him as a gunner, and a handful on backup kickoff returns.