If you are looking for some game tape check out the Chargers game here: https://www.youtube.com/watch?v=iz3YysPqA7A. Ty Johnson comes in for almost a whole series at 39:10 of the video (10:40 left in the 2Q). He looks good on tape and clearly is making the right reads for the lions primarily zone-based running scheme.
Kid has some talent but I think you guys need to pump the breaks on the Kamara comparisons or holding out hope that he is going to get 40-50% of the carries at some point this season. The Lions clearly believe KJ is the #1 back. Also there is no evidence this kid will be receiving dedicated goal line work or passing down work as those are clearly KJ specialty (look as his college usage/highlights for goal line and last week/last season for passing downs). It also is a fallacy to think that all of CJ's carries are going to go to Ty. A more likely scenario is you see those touches split between KJ and Ty Johnson.
Most likely scenario of touches I see is KJ 65-70%, Ty Johnson 20-25%, JD McKissic/Perkins 10-15%.