You could argue the same for DeBoer in general. He has some big wins to go along with some bad losses. We don't really know for sure if his style is going to work in the SEC (at least sufficiently to meet Alabama standards). Time will tell.
That was a big issue I had with Sheridan though. He wasn't a proven commodity, and while Milroe was justifiably blamed for a lot of offensive struggles, there also wasn't much from Sheridan to feel good about either. If he was to continue calling plays next season, the blame game could have shifted from Milroe to Sheridan, and then of course the idea would be may be if DeBoer just got the right OC then his offense would work.
We will now know for sure. DeBoer has his man running the offense, these are the minds behind his success at Washington and there is no inherited QB (no Sayin, no Milroe, two guys they brought in and Ty). If DeBoer's style of offense is going to succeed in the SEC, we will find out next season.