Troops tactics. How to level. Together or 1 by 1?

I’m wondering. I have fi 4 purple 4 star troops. If I level is it best to go around and level all 2 3 4 whatever so that they will be all together on the next level OR is it better to get one troop at highest tear first and continue with next?

And would it be preferable to do manna first or crit if you have the choice?

I have most 4 star on level 10 till 12. (Manna for gravemaker. ) what’s wise

So to have my troops as example. Should one first get all blues at 12 first an then get one of them to max tier or get them all to 13, 14 etc.

I don’t have any very fast heroes, if I had I would probably take 1 mana troop to 11, then focus on a critical troop to max. If you have a rainbow defense team for raid/war, then having a single high level crit troop with defence increase is important - imo more important than having several medium level troops for stacking.

Lol I was just thinking in raids and titans… but off course raid defence and war defence is nice… tx for this input. So for defence sakes 1 high level crit and def. Ev. Ok with this?