7* hermit yoda, 5* wampa, or more G12 gear pieces?

The biggest difference I have noticed is G11 to G12. However some of those G12 pieces have huge boosts to the characters stats. I myself am buying character shards that are harder to come by in other areas of the game before focusing on Hermit Yoda or Wampa. My guild would benefit more from me having Krennic than Wampa as of right now.

The best advice I would give you is to beef up your entire dark side roster. You have a lot of 7* DS guys but none of them are geared very high. Start buying the gear they need from the guild event store and other areas. This will not only help your guild in Dark Side territory battles but also in territory wars as well.