You can use Lavender or Convallaria instead of Gerbera. They have a good skill damaging 3 pests. And if you have her, use Strawberry Candle instead of Peach. Peach is really good but Solar Shrines from Strawberry Candle are broken.
And also, use girls in this order: Ardisia, Ivy, Gerbera, Night Phlox and Peach. Always use girls with multi-target skill first. The correct order in any case must be: 3 target skill - 2 target skill - 1 target skill - damage on 3 random target skill.
Also note that Solar Blast team are weak in term of pure power and rely only on Solar Blast. If you can't have a Solar Blast when fight start, they will be just useless and will take an eternity to kill the pests. BUT, kill full life bosses with only one Blast is so good...

I have been drowning in 5* hit girls in last month or so.

Since Plumeria event I have:

Rolled 10 and got Cactace Bride, Cyrtanthus, and Lady's Sorrel (plus 2 magic girls)
Got Clemantis from last event
Rolled 10 and got Flowering Peach (Bride) and Lagurus (HW)

Also Butterfly Bush is another hit girl waiting in the shop.