How do I beat Bossk and co? In GW

Vader is particularly potent against Phoenix, as he gets +56 speed from 5 rebels and 2 jedi. Focus on taking out vader first, using ezra/chopper to debuff the tanks when they taunt. Try to keep either han, vader, or both stunned until they go down. Kill order should be: Vader, Han, V Chewie, Bossk, CW Chewie.
Ideally, at your level you would also have an empire team ready to go as well for harder nodes. If you haven't already, start leveling/farming Vader, Emperor Palpatine (or get him next legendary), Thrawn (you'll need phoenix at least 5* to unlock him in a few weeks), Tarkin +1 (TFP or Royal Guard are easily accessible early on). Once you've got a good Empire team, play your first GW node (should be really easy) with Empire, using only basic attacks to keep their specials ready and charge up turn meter. After that, steam roll the rest of the nodes with Phoenix until you get to one they can't beat. Swap in your Empire team with preloaded turn meter, nuke that node, then switch back to phoenix until you get to another you can't finish.
Out of curiosity, what are your mods, as well? If you don't have them yet, you should have at least +60-80 speed fairly easily accessible at your level (eventually you'll want 100+, but that takes a while to get). Zeb and Hera should also have potency crosses to make sure their debuffs stick (may want 1 or 2 potency sets for Zeb, get him to at least 50%).

Sounds like you were just hosed. The GW matching algorithm randomly throws ridiculous opposing teams at you, sometimes as early as the halfway point.

It threw 81-85 Wiggs+Chaze+zJyn at me at the halfway point today. My squad is only 81, no zetas.

Just ran into this type of thing today. I'm lv 65 with PS, mostly 5* g7, zeb is 7*. Got to last mode of GW and it was a lv 75 Bastila lead jedi team. Ya real fun...

Last node it's annoying but understandable: it's the end of the sequence and there are 400 tokens at stake. It's the halfway point ones that really hack me off.

Switch to empire team they r the free to play way to go jedis r late game f2p not friendly early due to hard ones farming