I want Harper 2d or 4th. That is close to my starting point in any batting order. If Rendon were going, he'd be my other 2d or 4th hitter. Without him off, maybe I want Rendon 3d. When Span is back, I suspect we can slot him straight into leadoff, but until then, I'm more than OK with Werth there. It is 2012 all over again, when he was terrific in that slot.
Yunel's low K, contact-heavy OBP makes him a sneaky RBI guy even with his lack of power. I'm good with him 3d or 4th or 5th, right behind Harper or Rendon. It isn't the classic "protection" of the next best power guy behind the protected hitter, but it is a good way to get runners on and knocked in through contact. Maybe there is GIDP potential, but I think you'll get more contact with multiple guys on base this way.
RZ is the tough guy to slot. I think he's less of a hitter than Harper or a good Rendon, but I don't mind him 4th if Rendon is not doing well.
There's no ideal way to arrange things. When Span is back and Rendon is going well, the lineup comes close to writing itself - Span, Rendon, Escobar, Harper, RZ, Werth, SS, C. If Rendon isn't doing much, swap him and Werth or RZ.