How big is your roster? I've been playing since April of 2016 and I have everyone besides General Kenobi unlocked (my guild can't do Heroic yet). I use a multiple team/Turn Meter strategy. For example, on the very first node I use: Tarkin (L), Magma, Storm, TFP, and Death.
2: Barriss (L), Luminara, Ayala, Kit, and R2.
3: Phasma (L), zKylo, FOTP, Geo Soldier, Rey
4: Ackbar (L), Leia, STH, Biggs, and Lando
5: zQGJ (L), Anakin, Ashoka, Yoda, Mace
6: zMaul (L), Savage, Sidious, Dooku, Emp Palp
7: zVader (L), Palp and Maul from phase 6 who should have lots of TM, Royal Guard, Boba Fett
8: same team (it's my strongest) but sometimes I'll sub in Death from phase 1 or Barriss from phase 2 to make sure they have high TM for tougher rounds. (I want death to go first against Chaze or Shore teams to remove Taunt and Barriss to Heal if needed).
9: zVader, Palp, Maul, Boba, and RG
10: same team
11: same team
12: switch out Boba and Maul and put in TFP and Death. I run a full Empire on node 12 (sometimes 11) and weaken them as much as I can. 5/10 times I finish it without having to use any backup teams but even if I did I have ZMaul and all the other teams with high TM. The trick is to use only Basic moves to save all the specials for node 11/12. This strategy gives me 7-8 teams to fall back on and then some.