Yes, our situation is frustrating. However, I don't think the need is a roster spot for help. We could upgrade at TE or OL by replacing one of our existing players. We don't need to trade players who are low in the depth chart. There are always healthy, inactives. Let's look at the various situations.
OL, TE
As I indicated, we can upgrade if we wish to do so.
FB
We have an open roster spot. We can fill it, or not.
Harris
Harris is at the bottom of our RB depth chart. I see now reason to cut him because his isn't valuable in the 2019 offense. A top draft choice should be give at least some time to develop. Yes, it is disappointing that Harris isn't worth activating with Burkhead out, but I suspect that Harris isn't a top special teamer.
JoJuan
I simply don't understand your position. We activate 4 CB's for every game. JoJaun is the #5 in the depth chart, and therefore inactive. I expect him to be active if any of the CB's is inactive because of injury.
Bennett
Bennett is currently a very expensive backup. If someone were injured, he likely would gets lots more reps. A trade may be a good idea. The issue is value and fit. If BB doesn't see a lot of upside, then he should be traded and Cowart activated.