Matt Nagy wants to spread the football around. Cohen may dent into the carries of Howard. On top of that, Howard may get fewer carries due to the overall nature of the offense. This likely means more pass attempts from Mitchell Trubisky and less rushing attempts from Jordan Howard.
Since Howard has been drafted Allen Robinson, Taylor Gabriel, Anthony Miller, Trey Burton, Dion Sims, and Adam Shaheen have all been added to Cohen. They have overly relied on Howard in his first two seasons. Now, they want these seven other skill players to dent into the touches of Howard.
If Howard is a volume based runner, and he is not getting the volume, he may be inefficient. If he is inefficient while Cohen is efficient, it is going to stand out how much better Cohen is as a pass catcher. So, if Howard is not going to improve as a pass catcher, he is going to sink down the totem pole of this offense that may be clicking on all cylinders.
When you add in the lack of trust from the coaches and the questions that came to this offseason, there is a case to be made that 2018 will not be a great season for Jordan Howard.