Quality of contact stats are dubious. There really isn't much (any?) added information in them. The stringers / video "scouts" at BIS are influenced by results... I think for pitchers something like hard hit % probably ends up being just a proxy for other batted ball profile stats, like GB%.
If a guy has a low BABIP and a high GB% like Sanchez does, the stringers are going to tick a lot of soft contact boxes. It doesn't mean he has some causal skill in contact manipulation. The sample size issues are intense too. There isn't really any sample size where you can look at a pitcher's hard/soft% and say, a ha! that's why he has a low BABIP!
There's a reason that guys with very high hard hit % can be super good (Tanaka and Corbin are among the leaders since 2010) and guys with low hard hit % can be super bad (the creme de la creme include Jamey Wright, Eric O'Flaherty, Javier Lopez, Jim Johnson, Randy Choate).