This is the plan I’d suggest players follow nowadays, I threw in some specific thinking towards your situation where appropriate.
For credentials… I’ve just entered my 3rd anniversary daily rewards phase, have everything champed through 5* metas and I am currently working on champing those that are useful when a week hits that I don’t have anyone boosted to run for PVP while maintaining my overall plan. I do and have played fairly competitively during this growth so the plan below is tailored to that approach.
I mostly spend bottom up, as that increases the flow of rewards most quickly, but I have some caveats:
2s I spend on immediately to keep them cycling.
New 3s are immediate also, then start spending towards a team that can help your play out. I honestly don’t know who is considered useful at 3* anymore, I mostly leaned on Dr. Strange, Iron Fist and Luke Cage during that phase. Champ em all. Dupes only get spent on once at 64? covers so they’ll spit out that extra LL.
4s are where it gets tricky. Find yourself some meta teams and go after those first. Then prioritize those that feed, then move to 5* meta choices but possibly only soft-capping them somewhere convenient (360 is a widely accepted stop point and allows them to play like champed 5s during boost weeks but we do have pvp MMR changes coming so who knows). Whether you soft cap or not, for 5s I suggest only putting ISO into them in a big lump to start for MMR reasons.
I personally moved from soft-capped metas to a single champ 5* while continuing to work on my 4s and then saved up for a long time, moving fully to 5* with 10 or so of the top picks. The advantages of soft-capping have probably mostly dried up actual game-play wise but there’s still pretty healthy debate on the subject. As a growth strategy I think it makes good sense as getting your 4s spitting out rewards is CRUCIAL to your roster growth.
I don’t think there’s a huge rush to champ any more 5s once you’ve gotten through most of the meta. Cases vary but my next priority for 5s would be those that are good when boosted.
*In your case, I’d champ Hit Monkey and Kang just to have choices for combating immortal teams in PVP. Magik and Jeff can get left on the back-burner for as long as you please, neither are particularly useful imo.
After 5s go back to 4s and ideally you’ll get them all champed (following my previous ahem “wider bottom” up strategy, I champed literally every 4 there was before moving onto putting more than “soft cap” ISO into 5s, but I wouldn’t suggest that now). Even the ones that don’t feed now could in the future and give you LLs at every 10 covers. Getting your 4s larger means better rewards when you draw for 5s and will become your biggest consistent point of champion income (unless you go hard on classics, I suppose).
I hope that wasn’t needlessly complicated and meandering.
