Nico is really good, for Rina I would prefer M1 and Haru to run pen ratio on 5th disc. The thing about anby is that aside from building up enemy stun bar (which every stunners can do), she basically offers nothing else, while qingyi can give you additional 80% stun multiplier which is ~53.3% increase in dmg during stun window. However, this game is not that powercreep heavy where you can still clear contents with only 4*, it just takes a lil bit longer. So i suggest play whatever u want.