I was very surprised to see that Engels joined NOP. I don't think that he's a great fit for any of the Nike groups (OTC is a graveyard for mid-D, BTC is long distance focused) but especially NOP. For one, Salazar is not shy about the fact that his runners run their easy days pretty fast. The men are well under six minute pace, the women are in the mid-six minute pace range. One of the main reasons that Engels left NC State was they take their easy days too fast. There are multiple interviews where Engels states that they ran their easy days too fast for him and he consistently got injured. Once he transferred to Ole' Miss he started to take his easy days easier and he stayed healthy. He'll have plenty of recovery and cross training tools at his finger tips to help him stay healthy, but running those easy days fast could be tough for him. Engels has also been relatively lower mileage compared to what the Oregon Project does. Hes gotten as high as 80 but a recent interview in runner's world says that he's in the 70's range.
The timing of his decision is very interesting as well. Typically, we see athletes join a group before the U.S. Championships or after the summer racing season. This year, we saw Josh Thompson and She Collinsworth running in BTC and OTC singlets respectively at USAs. Same thing with Hasay and the Oregon project in 2013, Shelby Houlihan and Colleen Quigley in 2015 with BTC, and Courtne Frerichs in 2016 with BTC. Jenkins and Centro waited until long after the US Championships to join the Oregon Project. Ryan Hill waited until his summer season was over as well. My guess is that if Engels made the team, his contract would be X and if he missed the team it would be much lower. Since he missed the team he was likely forced into this decision because it was much more lucrative than staying with Vanhoy at Ole Miss.
It'll be interesting to see how he develops over the next few years. I wouldn't be surprised to see him drop NOP and go back to Vanhoy in 2019 or 2020.