Fangraphs has wRC+ for minor league hitters, which does some adjusting for league and park, and Gordon was doing pretty well (above average) up until this year, even with the lack of power.
His wRC+ lines up with my expectations. Previous to 2017, he was a solid, though unspectacular, hitter. This season is waaaaay above that. It will be interesting to follow if/when that BABIP normalizes.