Gallo is a hitter for which OPS is incredibly misleading.
He fails to put the ball in play so often he more than cancels out the few HRs he hits.
He has 16 HRs...and 30 RBI.
Thirty.
3 sac flies IN HIS CAREER.
SLG is only valuable in that it contributes to scoring runs. When you don't drive in runs, theoretical mumbo jumbo is just that...mumbo jumbo. It doesn't demonstrate some greater understanding of baseball. In fact, just the opposite.
Gallo is not a good offensive player. He's awful. Much worse than a cursory glance at OPS indicates.
His 16 HRs do not represent a positive for this offense.