Fennel seems a bit out of place. I understand the point of covering all weaknesses but it's not guaranteed and Knotweed don't get any weakness damages buff to really need it. Evergreen Candytuff may be more interesting since she is magic herself.
You can use Red Spider Lily School and give Guardian Type to Golden Lace while Knotweed keep her Attack type. She will still buff Knotweed and makes Golden Lace more offensive with her intercept. And all the other girls will benefit her 100% intercept anyway thanks to Golden Lace miss debuff.
Usagigoke is good too but for other reasons.
Or you could go for less Crit and use both Usagigoke and Red Spider Lily without Dusty. Less damages but more survivability if you need it.
For weakness attribute, you can still use FM to give the attribute you need at the right moment.
Vanda after promotion can be used as filler too. Or you can look for another promoted girl but there is so much that I lost track of them and can't say who do what anymore...

Anyway, I think it's better to strat with as much girls as you already have. Knotweed-Golden Lace-Dusty-Angelica is a good base core. Just look for Usagigoke or Spider Lily depending on who came first. The mosrt important is knowing what you want to focus on. Raw damages or Intercept.

Also, it seems changing girls' Types works again.

Meanwhile, I made this team based on Tritoma:
New Flower Tactica [aka share your best teams here]-team.jpg
I wanted to do something very offensive without Ancient Flowers. It destroy Honeyshucle in one turn, even skipping her healing.
the idea is maxing Tritoma's damages for her combo hit. Asian White Britch is perfect for that with attack and weakness damages, Spring Star School cover skill damages. Orange fish the job with more attack, more crit and more weakness damages. And bring Blue weakness for Honeysuckle fight.

I'd like to replace Stockes' Aster with Dracaena of Hinoki but I don't have them. Cardamine Lyrata (Halloween) would be fun too. Maybe better as she gives Act Again for Asian White Britch, Spring Star and Orange.