I'm not sure who to get either; right now my helper squad is nearly capped on crit chance (25% from Kugaisou, 20% from Colchicum, 25% from RG Black Locust).

I could swap Mei or Anemone in for Colchicum without wasting crit chance, I could get Cactus and only be wasting 5% crit chance while still getting another big boost to crit damage on top of the double strike chance, or I could get Dogwood and start building a solar burst team alongside Ghost Weed (plus I'd like to have the 6* version of that squeaky fire/water mage at some point).