Your responses were so helpful and I’ve found four combos that I really like! Would love to hear your order of favs and why! I really appreciate your time! If you like the first name but don’t like the combo that helpful to know as well. Hoping one really stands out!
Henry Evan Daphne &
Owen Arthur
Theo Everett
Arthur Jack
Owen Everett
[name_u]Owen[/name_u] [name_u]Arthur[/name_u] — I think [name_u]Owen[/name_u] is a smidge too close to [name_u]Evan[/name_u], but I do love this combo.
[name_u]Theo[/name_u] [name_u]Everett[/name_u] — Fits well with your others.
[name_u]Arthur[/name_u] [name_u]Jack[/name_u] — I love [name_u]Arthur[/name_u] 
and really like this combo with your others.
[name_u]Owen[/name_u] [name_u]Everett[/name_u] — Same as above about [name_u]Owen[/name_u], and I like [name_u]Arthur[/name_u] better than [name_u]Everett[/name_u].
What about [name_u]Arthur[/name_u] [name_u]Dean[/name_u] vs [name_u]Arthur[/name_u] [name_u]Jack[/name_u]? Prefer one?
I’d vote for [name_u]Owen[/name_u] [name_u]Arthur[/name_u]! [name_f]My[/name_f] thoughts-
[name_u]Theo[/name_u] [name_u]Everett[/name_u] - I like [name_u]Theo[/name_u] but feel that it seems too much like a nickname next to your oldest 3 children’s names.
[name_u]Arthur[/name_u] [name_u]Jack[/name_u] - [name_u]Arthur[/name_u] is a lovely name, this combo is my second favorite! To answer your question, I may like [name_u]Arthur[/name_u] [name_u]Dean[/name_u] slightly more, but if one middle name has personal/familial importance I’d go with that one!
[name_u]Owen[/name_u] [name_u]Everett[/name_u] - I like both names, but to me the en sound in [name_u]Owen[/name_u] runs into [name_u]Everett[/name_u] in a way that does not roll off the tongue, that’s not important to some but worth considering.
[name_u]Owen[/name_u] [name_u]Arthur[/name_u] - my #1 pick, it was between Own and [name_u]Arthur[/name_u] and both names are lovely and would make a great addition to your current sib set! [name_u]Owen[/name_u] doesn’t feel too close to [name_u]Evan[/name_u] and I just love the flow of [name_u]Owen[/name_u] [name_u]Arthur[/name_u]!
Good luck!
[name_u]Arthur[/name_u] [name_u]Jack[/name_u] or [name_u]Owen[/name_u] Everett!!!
[name_u]Arthur[/name_u] [name_u]Jack[/name_u] is the one that stands out for me and fits nicely with the siblings (different sounds but same style). And I definitely prefer [name_u]Arthur[/name_u] [name_u]Jack[/name_u] to [name_u]Arthur[/name_u] [name_u]Dean[/name_u] (Jack matches in style whereas [name_u]Dean[/name_u] doesn’t).
I do find [name_u]Owen[/name_u] a bit too close in sound/pattern to [name_u]Evan[/name_u]. And [name_u]Owen[/name_u] [name_u]Everett[/name_u] very much so.
[name_u]Theo[/name_u] [name_u]Everett[/name_u] is very handsome but [name_u]Theo[/name_u] is too nicknamey to me and [name_u]Everett[/name_u] too close to [name_u]Evan[/name_u] (I know it’s only a middle name but it still counts!).
All these names sound fine together to me…
[name_u]Owen[/name_u] [name_u]Arthur[/name_u] is lovely. [name_u]Arthur[/name_u] is so warm and rich.
[name_u]Owen[/name_u] [name_u]Everett[/name_u] is nice. Actually I prefer [name_u]Arthur[/name_u] and [name_u]Everett[/name_u] to [name_u]Owen[/name_u] now.
[name_u]Arthur[/name_u] [name_u]Jack[/name_u] – like both names, but [name_u]Jack[/name_u] sounds funny to me as a middle name.
I don’t care for [name_u]Theo[/name_u] myself, but it’s a fine name.
I pick [name_u]Theo[/name_u] Everett; [name_u]Henry[/name_u] & [name_f]Daphne[/name_f] both have a bit of a vintage vibe even though [name_u]Henry[/name_u] is really popular right now, [name_u]Evan[/name_u] has a more contemporary vibe, not vintage but also not entirely modern - [name_u]Theo[/name_u] seems to fall somewhere in between the two vibes while also being its own thing, which I really like.
[name_u]Arthur[/name_u] makes [name_u]Evan[/name_u] stand out in the set as not being vintage but would be my second favourite.
[name_u]Owen[/name_u] has always felt rather vibe-less to me; it just feels a bit boring to me personally so it’s my least favourite. It fits the set but it’s just not my favourite.
[name_f]My[/name_f] vote goes to [name_u]Theo[/name_u] [name_u]Everett[/name_u]. [name_u]Owen[/name_u] is a tad too close to [name_u]Evan[/name_u] for me. [name_u]Theo[/name_u] goes very well with your other children’s names, and so does [name_u]Everett[/name_u].
definitely love theo everett 
[name_u]Theo[/name_u] [name_u]Everett[/name_u] is great!
[name_u]Arthur[/name_u] [name_u]Jack[/name_u] stands out to me!
[name_u]Owen[/name_u] [name_u]Everett[/name_u]
[name_u]Theo[/name_u] [name_u]Everett[/name_u]
[name_u]Owen[/name_u] [name_u]Arthur[/name_u]
[name_u]Arthur[/name_u] [name_u]Jack[/name_u]
I really like [name_u]Theo[/name_u] [name_u]Everett[/name_u], my second pick being [name_u]Arthur[/name_u] [name_u]Jack[/name_u] 
[name_u]Arthur[/name_u] [name_u]Jack[/name_u] is my favourite. [name_u]Or[/name_u], if we’re allowed to mix and match, [name_u]Arthur[/name_u] [name_u]Theo[/name_u].
[name_u]Arthur[/name_u] [name_u]Jack[/name_u] is my favorite! But I also love [name_u]Theo[/name_u].
[name_u]Theo[/name_u] [name_u]Everett[/name_u] is super handsome and a great complement to your other three!
This one stands out to me 
owen everett - i’m not a huge fan of owen or everett, but it’s just my personal preference. i think the combo as a whole gives me an overwhelming foresty feeling. owen is just owl to me for some reason, and everett makes me think of everest and evergreens.
theo everett - i like theo, but i prefer theodore, as it’s a more formal name to lean back on. theo everett gives me a very modern vibe, which i’m not a huge fan of.
owen arthur - arthur is adorable, and i definitely like the owen arthur combo much more than owen everett. quite cute and still masculine.
arthur jack is soooo darling. plus, it will definitely grow with a person. i can totally picture a little toddler arthur and a grown man named arthur. jack is nice and classic but not at all dated, which i love.
[name_u]Arthur[/name_u] [name_u]Jack[/name_u] is absolutely my favorite, but for you, [name_u]Theo[/name_u] [name_u]Everett[/name_u] comes in verrry close at second place! Both are just beautiful with his brothers and sister.