It's a little surprising given how high Stott, Turner and Harper's OBP is. But it also shows it really doesn't matter. And there's probably still a case that Schwarber is batting too low given he has the highest OBP and OPS on the team. Either way, scoring first highly correlates with winning for the Phillies, and they are doing it this year just as well as last year.
The problem is really that they still don't have a better #4 option, nor a RHB for it. And even if they did that would push Schwarber to 5th on the days Stott leads off.