6* Chewie is easily obtained by OG Hunters (Even without Dengar if your willing to restart indefinitely until R2 doesnt smokescreen.) I had G12 zBoba with G10 IG-88 G9 Greedo G8 Cad/Zam and I got 6* after about 80-90 tries (And I have dengar I did this just to see how far I could get without my 7* Dengar and Bossk) But Tier 7 was next to impossible without Dengar. Add in Dengar and leave out bossk and I could do 7* Chewie I got it down to Just Lando and R2(About 100 tries later) before I quit and went through it again with Bossk + Dengar and was able to clear it without more then 4 tries.
Key thing to understand that is with out Bossk and under a boba lead all hunters need a total combined Potency of about 350%+ as well as decent Prot/Health secondaries as well if they are under G10. This being said I do believe zBoba pulled a ton of weight on my potato hunter squad and without his Zeta I dont think a 7* Chewie without Bossk/Dengar is possible (My G12 zBoba was also just below Arena Quality modded +80 Speed +60%Potency +16000Protection + 4500 Health)
Secondary point of interest is knowing when to use your Thermals and having Zam with enough offense to take out users with 2-3 TDs stacked onto them as she auto detonates any Thermals using her basic. And NEVER use 88s special until Chewie/Han are DEAD! They are the most dangerous units to feed TM to and EVERY debuff and TD will give the whole team TM under ROLO lead.
Even with all the advice mentioned above I have seen friends and guildmates take home 7* chewie using different tactics and less tries (For the lucky ones) so just dont give up and keep banging your head against the RNG wall of hopelessness
