Galactic War.. Should I farm Phasma shipments?

Thanks for all the detailed opinions guys. @Cleaner generally I finish the day ranked 100-200 in arena, I don't play this game all the time. Finding GW a bit difficult I tend to get up to the last 2 battles and can't complete a full GW (only fully completed 2) @Render you make a fair point. I think of both were 7* and fully geared I would lean more towards Lumi maybe I just need to give her more time to grow stronger? Thanks @DarthVanio good feedback :)