I think Slovis would have looked much better if the offensive personnel were all in the system for a long time together. It wasn't just the OLine that stunk, the other personnel groups on offense contributed to the stalling of the offense. They just missed so many assignments when Slovis played.
The system was also not a perfect fit as having a running threat is essential, but the sloppy play by the offense made Slovis look worse than he was.