Arena squad advice needed

Merilon

Hello and happy New Year everyone!

I am mostly f2p (except Doku pack) and my arena team consists of Sid, Doku, Lumi, JC and old Daka. This Setup works quite well for me. Usually I managed to get top 10 while I was still levelling up and I never dropped lower than rank 30-40 over the 24 hours.
Now that I reached lvl 60 I also managed to snipe rank 1 three times in the last four days.
Even if one should not change a winning team, I am thinking about integrating Phasma into my squad, because Lumi is finished 7* and thus Phasma will star up fast as well. At least much faster than Doku, who is still sitting at 4 stars.

So my Idea was to replace Doku with Phasma (4* as well) once geared up. But I wonder how that would affect my team when defending, since the idea of the team (thanks to swgoh cantina) is to time out the opponent and achieve a draw rather than destroying the enemy team. I am affraid that the lack of Doku's stuns and bonus attacks can not be compensated by phasmas abilities as a leader.
So the other possibility would be to throw out my squad leader Sid for Phasma in order to gain more bonus attacks and stun procs. But this would bring the disadvantage of having no heal immunity debuff and thus making it very hard for the AI to bring down at least one or two enemies which is probably equally important to keep the fight going for 5 minutes.

Any thoughts and suggestions regarding the possible replacement options are highly appreciated!