When everyone is healthy, I'd go:
XB - SS
Sizemore - LF (or CF if JBJ gets day off). Gomes gets some starts and PH in other games.
Pedey - 2B
Ortiz - DH
Napoli - 1B
SV - RF (Nava gets games at RF (two a week?) and 1B)
JBJ - starting CF
WMB - 3B
AJP - and Ross
Gotta hava AJP/Ross and WMB at the bottom two slots due to low OBP. SV/Nava decent protection for Napoli, but also along with JBJ serves as a 2nd top two of the order for the AJP and WMB.
JBJ isn't getting leadoff for some time, they are happy enough he stopped chasing pitches and stopped his long swing from ST. No further pressure/changes for now.
When SV comes back: Carp to be dealt or put onto the DL (wink wink). Carp seems the type to be grateful just to be on a ML roster, or on the DL. Gomes won't go along with that. Roberts (more likely since he can't play SS) or Herrera dispatched when WMB back.
If Sizemore tires/gets hurt or JBJ still tearing it up by May 25th then JBJ 2nd.