There's also the trade cost. I'd rather just throw Pompey out there, or if you're spending 10M on a meh CF, just give Colby a bit less than that and a pack of chicken hot dogs and he can fill the position with more upside and more defensive competence than Fowler.....
Pompey = upside, if he fails...
Saunders = palatable CF insurance (Dirks/Pillar fill LF), if Saunders is hurt...
Carrera = replacement dude with a reputation for CF defense, strong strike-zone discipline, and plus speed.
It's really not a terrible situation. 2B is much worse, obviously (a bunch of s*** and then pray-4-Travis).