Delphina, August, Juniper, Leilani & Cassius (Latin)
Delphina, August, Juniper, Leilani & Piers (Greek meaning rock)
Delphina, August, Juniper, Leilani & Tiberius (Latin river name)
Delphina, August, Juniper, Leilani & Moss (nature-y)
Delphina, August, Juniper, Leilani & Hiram (Hebrew origin, but my Dutch relative is named this)
Delphina, August, Juniper, Leilani & Cornelius (Latin)
Delphina, August, Juniper, Leilani & Phineas (Roman emperor, means “oracle”)
Delphina, August, Juniper, Leilani & Dashiell (Just looked like it fit in with the others)
Delphina, August, Juniper, Leilani & Bruno (international and very distinctive from the others)
Delphina, August, Juniper, Leilani & Ivan (same reason as Bruno above)
Delphina, August, Juniper, Leilani & Crispin (Latin)
Delphina, August, Juniper, Leilani & Quintus (Latin- means 5th, cool because this is your 5th child!)
I tried to draw mostly from the Greek/Roman vibe I get from your sibset, the “ph” in Delphina, August- after the Emperor Augustus, and Juniper is kinda like the mythological god Jupiter. Also, in addition to the nature vibe (with the flower, tree meanings), it has an international vibe as well due to the different cultures the names derive from. I like how all of your name are very distinctive yet somehow work well together, so I tried to include names that continued the distinctiveness and also keep it a little tied in.