The first and easy thing to do is to sort through them by basic, matching/similar abilities. That'll Team Synergy 101. The 4* Knights will follow the same pattern as the 5*.

+Atk% ~ Canna, Peach, Setaria
+Def% ~ Bipinna Cosmos, Southern Cross, Waterlily
Nest Panel ~ Japanese Iris, Gentian
Solar Power ~ Calla, Lavender, German Iris

Camellia ~ +Atk/Def%
Orchid ~ +Atk%, Nest Panel, Speed as needed
Dipladenia ~ Nest Panel, Speed as needed
Lilac ~ +Atk%, Speed as needed

Another option is to disperse your +Def% abilities across the squads, as its efficiency drops off as the Pests' Attack rises. Also having dodge units myself, like Waterlily and Ionocidium, you can stack some together to capitalize on survival, so [Setaria, Waterlily & Southern Cross] is another thing to consider.