I prefer the Thielen for Harris deal, because Henderson is banged up already on somewhat limited work, plus he will be competing with Sony Michel for touches going forward, and we have no idea what the breakdown of the RBBC will be in LAR once Michel gets up to speed on the offense.
On the other hand, Harris has a tough floor against good defenses, which we saw last week against the Saints. He’ll have another tough matchup this week against the Bucs, before he gets a juicy matchup against Houston. Harris has shown to be very matchup dependent, but he can get you points against lesser defenses, giving him much better upside. Plus the Pats want to use the running game as much as possible to take pressure off their rookie QB.
Regarding the option of trading for CEH, don’t. He doesn’t get much work near the endzone, since Mahomes and the passing game own that territory. Case in point: His only touchdown this year came from a pass. And since CEH isn’t utilized much in the passing game (Mahomes checkdown? Not happening), that leaves CEH very reliant on long runs for touchdowns, and that’s not a good place to be for an RB.
You’re better off with Harris.