I don’t know if you’re looking for help on the middle names or on the whole name…so here goes 
I personally think that [name]Wolfgang[/name] and [name]Logan[/name] jar. [name]Wolfgang[/name] [name]Orion[/name] is eclectic, but meaningful; unusual, but approachable with its nn. [name]Even[/name] though [name]Logan[/name] doesn’t hold a high rank for girls (the only one I “know” is Logainne from Broadway’s [name]Putnam[/name] County Spelling [name]Bee[/name], the sweet, awkward child with two gay parents who wins!), the name is ranked at #17 among boys. She’ll probably have other Logans in her classes, which (even if they’re boys) means she’ll be [name]Logan[/name] E. or Girl [name]Logan[/name]. To me, the name has an All-American, popular vibe which pulls it further from [name]Wolfgang[/name]'s feel.
I think [name]Azure[/name], [name]Daphne[/name], and [name]Aurora[/name] are incredible with [name]Wolfgang[/name]. I think [name]Azure[/name] is particularly great because there are several species of butterflies called Azures: [name]Summer[/name] [name]Azure[/name], [name]Spring[/name] [name]Azure[/name], Small [name]Azure[/name]. If you wanted to take it in that longer, more feminine direction, you might try [name]Azura[/name]. [name]Daphne[/name] makes me smile; it complements [name]Wolfgang[/name]'s heavy sound with something airy and light. [name]Aurora[/name] is gorgeous; it has the nature imagery of the [name]Aurora[/name] Borealis and light, but it has a heavier sound to go with [name]Wolfgang[/name]. Icing on the cake? [name]Rory[/name] is a great, masculine nickname. Here are some more suggestions, though.
For a stronger, unisex name, I’d turn to: [name]Bronte[/name], [name]Titian[/name] or [name]Hopper[/name], [name]Brooks[/name] (works “river” in), [name]August[/name], [name]Timber[/name], [name]Sage[/name], [name]Pax[/name]/[name]Paxton[/name], [name]Indigo[/name], [name]Gray[/name], [name]Arlo[/name], [name]Archer[/name] (isn’t [name]Orion[/name] an archer, too?), [name]Schuyler[/name]/[name]Skylar[/name], [name]North[/name], [name]Rigby[/name] or [name]Sloane[/name].
For a longer, more feminine name: [name]Althea[/name], [name]Marcella[/name], [name]Roxana[/name], [name]Rowena[/name], [name]Calliope[/name], [name]Willa[/name] (instead of [name]Willow[/name]), [name]Rosamund[/name] (got your [name]German[/name] descent), [name]Adelaide[/name], [name]Penelope[/name].
For middles, I think [name]Butterfly[/name] lacks the subtly and beauty of [name]Orion[/name] (plus two words in one name is a lot if you plan to use [name]Elm[/name]). If [name]Mariposa[/name] doesn’t do it for you, here are more names incorporating that meaning: [name]Nova[/name] (Hopi: “chases butterflies”), Kimama ([name]Shoshone[/name]), Aponi (not sure which Native American tribe this originates from), Papillion (French), Euthalia (a genus of butterflies), Atala (a species), and Mazarine (for the species Mazarine [name]Blue[/name]).
I also think it would be really cute to connect your children with constellation/star names. What about using [name]Electra[/name] (in the Perseides), [name]Estelle[/name]/[name]Estella[/name] (“star”), [name]Seren[/name] (“star”), [name]Nova[/name] (a kind of star AND it has the butterfly meaning!), [name]Halley[/name] (the comet), [name]Lyra[/name] (constellation), [name]Columba[/name], [name]Andromeda[/name], [name]Thalassa[/name] (a star), [name]Ariel[/name] (a moon), [name]Phoebe[/name] (a moon)…There are tons more.
So I think [name]Wolfgang[/name] [name]Orion[/name] would be great with…
[name]Azure[/name] [name]Daphne[/name] [name]Elm[/name]
[name]Azure[/name] [name]Nova[/name] [name]Elm[/name]
[name]Azura[/name] [name]River[/name] [name]Phoebe[/name]
[name]Daphne[/name] [name]Electra[/name] [name]Elm[/name]
[name]Daphne[/name] [name]Lyra[/name] [name]Elm[/name]
[name]Daphne[/name] Euthalia [name]Elm[/name]
[name]Aurora[/name] Marazine [name]Elm[/name]
[name]Aurora[/name] [name]River[/name] [name]Estelle[/name]
[name]Bronte[/name] [name]Columba[/name] [name]Elm[/name]
[name]Rosamund[/name] Aponi [name]Elm[/name]
[name]Schuyler[/name] [name]Nova[/name] [name]Elm[/name]
and so forth. I hope this gives you some more ideas. If you want to stick with [name]Logan[/name], maybe [name]Logan[/name] Aponi/Euthalia/Mazarine [name]Elm[/name] would do the trick.
Best of luck. Sorry for the novel…