I find this thread very interesting as perception is, as always, limited to experience. So I have this one ally who I use when they are available to beat the 80 stamina maps and they have a full 6* Team - Cherry, Dogwood, Mei Plumblossom, Kerria, and Daisy all evolved and lvl 51 per my highest lvl, I don't know what they actually are. I just assumed this was how it's done (as in you're supposed to build up 6* teams...note the plural...but reading this thread makes me feel like I hit the ally jackpot since this team crushes every map I throw them at and apparently it's not common to have that many 6*s.
Unrelated is St. Paulia...am I missing something about her? I see that character name come up a lot in discussion and I have her but I haven't leveled her and I feel like I should....