well, as always, since p1, p3 and p4 have weird mechanics, the only acceptable phase for normal teams is p2. there's not much theorycraft there tho. just the meta team healing themselves, assisting each other, and doing nice damage. the assist cant be countered, so its a big plus there.
my damage there on the first try was 9.3M, without practicing before obviously, and while i still didnt have DF zetad (but it doesnt matter at all for HSR) so i guess with nice practice and nice modding (bast isnt part of my arena team so shes not modded well) can pass the 10M for normal people like us, not skelutrix that use god-mode mods :)
https://cdn.discordapp.com/attachments/458006234579337220/503844010880925697/Screenshot_2018-10-21-20-36-55-289_com.ea.game.starwarscapital_row.png