I think that several players in your core 19 are competing for roster spots.
- Blount appears to be a lock but if Gray and Gaffney outperform him he may be released after week 1, (they can keep until then because of his 1 games suspension.)
- Bolden is in competition with Cadet for the 3DRB/ST player role.
- Develin and Hooman will be in competition for the FB/TE role
- Chandler and Derby will be in competition for the #2 TE role.
- Of the group of #3 WRs and Joker TEs - Amendola, Wright, Davis, Gibson, Boyce, Dobson, Tyms, and Harper, I think 3 to 4 make the team.
- Wendell and Kline will be in competition, and I expect them to bring Connolly back in the next few weeks.
The only locks I see on this team are -
QB - Brady, Garoppolo
RB - N/A
WR - Edelman, LaFell, Slater
TE - Gronkowski
OL - Solder, Vollmer, Cannon, Stork, Jackson, Mason
DL - Jones, Easley, Brown, Ninkovich, Sheard, Grissom, Flowers
LB - Collins, Hightower, Mayo
DB - McCourty, Richards
ST - Gostkowski, Allen
Others may be very likely to make the roster (Siliga, Butler, Ryan, Harmon, Amendola, Blount, etc.) but they are not locks and not players I would refer to as “core”.
I'm using the word core to mean "almost a lock" and to mean that these players are very unlikely to beaten out for a roster spot. Obviously, you continue you belief that raw rookies will kick out veterans on a top team, but that's fine. We all have our biases.
RUNNING BACK
Your post indicates that
1) Blount, Gaffney and Gray are competing for one spot.
2) Cadet and Bolden are competing for another
Well, that gives you a roster of TWO running backs, including a special teamer. I find that to be extremely unlikely.
Blount could be beaten out for the starting role. Even so, he would not be cut. We need at least two 1st and 2nd round running backs. If you think that BOTH Gray and Gaffney will beat out Blount, I think that you are being unreasonable. There are TWO roster spots here and Blount will have one of them.
With regard to our 3rd down back, I don't have a clue with regard to who makes the roster. You think that Cadet and Bolden are competing for the position. I have it as Cadet, White and perhaps someone TBA.
You think that Bolden will not make the team as a special teamer. I think that he is is a backup as a 1st down back, a backup as a 3rd down back and a key special teamer. That enough for Bolden to make the squad as the 4th RB.
FULLBACK
Belichick and Josh like to have a fullback. They have one they like in Develin. If someone that is acquired can beat him out for a roster spot, that's fine. However that player is NOT Hooman. Hooman is incapable of being a fullback. Hooman is Gronk's backup. He stays only if Belichick values him in that role.
TIGHT END
Read my lips. Chandler is not going to be cut for Derby who may or may not make the Practice Squad.
There is competition for the 3rd TE roster spot (and 4th if we have one). Derby will get a look but is unlikely to beat out Davis, Wright, AND Hooman.
WIDE RECEIVERS
I think that you have too many. Also, if we keep FIVE wide receivers, Amendola will certainly be one of them.