This thread is hard to follow, but among starting TEs, Schultz is in the bottom third as far as receiving ability. The gap between he and Jarwin, as receivers, is massive.
To
@CowboysExchange 's point, there's really no reason why he should see 70% of the snaps, when he's keeping Brown/Wilson or even Pollard off the field. He simply does not have the athleticism required to force defenses to defend him in the seam, which is why we see Lamb there so much. In a vacuum, that's not a problem, but long-term, it greatly reduces the offense's ability to be creative.