Agreed - deal Bauer, Disco or Mahle if you need to use one of them to fill another hole. Those 3 are replaceable in one form or another. Castillo and Gray are not.
I don't hate the Seager/Pollock for Iglesias + idea. But the + would have to be some more minor pieces, Pollock's deal looks pretty bad now.
Ideally I'd just spend money on Didi, trade lesser pieces for a true CF and spend the remaining cash on the bullpen.