The facts don't bear this out. Lewis got 15 carries Week 1 when Blount was suspended but had more targets than carries the rest of the way. Lewis' PT came at the expense of White, who basically didn't carve out any kind of role until Lewis got hurt. (27 snaps in the 7 games Lewis played, including two healthy scratches). Lewis is a little
different player than White, but he (and Travaris Cadet) was more in that mix than in the early-down mix.
Wait a second. Lewis had more targets than carries the rest of the way in 2015 before his injury, but it certainly wasn't going because he was losing to carries to Blount. Be careful when not looking really deep into the numbers.
When Blount returned from suspension in week 3, he got 18 carries to Lewis' 8, but that's because it was a 51-17 blowout of Jacksonville, in which Blount was basically handed the ball over and over again in the second half. He had 16 of his 18 carries in the 2nd half, when the game was out of reach. Lewis dominated the snaps in the first half when the game was still a game.
In week 4 against Dallas, Blount got 13 carries to Lewis' 6, but 6 of Blount's carries came on one drive in the 3rd quarter, and 3 others came in the 4th when the game was over. Dion played 71% of the offensive snaps to Blount's 29%. This was a 30-6 Patriots win.
In week 5 against Indy, again Blount had 16 carries to Dion's 4, but 9 of those carries happened in the last seconds of the 3rd and then the 4th quarter, mostly after the Patriots had taken a 2 score lead and were trying to salt it away. Let's also not forget that this is BB's MO against the Colts going back to Jonas Gray. Pound the rock. Lewis outsnapped Blount 57% to 41%.
In week 6 against the Jets, Lewis was inactive, and the Patriots completely abandoned the run as a result. Brady had 4 carries, Blount had 3 and White had 2. Blount only played 8 snaps.
In week 7 against the Dolphins, a 36-7 beatdown, Blount had 17 carries to Lewis 6, but Lewis outsnapped him 54% to 38%. In fairness, this was the first time Blount was featured at all in the 1st half of a game. He carried the ball 4 times on the Pats opening possession, leading to a Gronk touchdown. He had 7 more carries (for 12 yards) in the 1st half, and then wasn't really seen again until the game was effectively over.
In week 8, Dion was playing really well until he blew out his ACL against the Redskins, and then Blount had a monster game.
Needless to say, I don't think Blount was handed anything in 2015. If anything, his role was pretty clear. He was second fiddle to Dion Lewis until the game got out of reach, and then Blount would come in and finish off the fourth quarter (kind of like Clock Killin Corey Dillon). Dion was in the game on almost every meaningful snap to start that season until his injury. Once Dion went down, Blount fell into the role of early down back.
In 2016, I think the Patriots believed they didn't need to upgrade the position, because they had James White, and because they knew Dion was coming back. Sure enough, once Dion came back, he played a few games and got his feet wet (incredibly, he played exactly 25% of the snaps in his first three games back, that's impressive by the training staff if planned) and then quickly overtook Blount until by the end of the season and in the playoffs, Blount became a non-factor except for when the games were out of hand, just like it was with Dion in the early part of 2015.