My least favourite is Darwin Elliot. I'm surprised a lot of people don't like Percival Julius actually, because that's one of my favourites on the list! Perhaps Percival Darcy or Percival Albert works better though.
I'll rate them out of 10:
Frederick Archer- 5, nice but doesn't stand out to me
Darwin Elliot- 3.5, it doesn't seem as romantic or elegant as your other choices
Crispin Avery- 7, I love Crispin but dislike Avery. Crispin Alistair or Crispin Albert?
Alistair Henry- 8, very sophisticated
Leopold Darcy- 10, I love both names and especially Darcy! (partly because of Mr. Darcy)
Percival Julius- 9.5, I agree something seems a bit off about the combo, but I love the two names too much individually!
Phinneas Aubrey- 7, I tend to dislike the "ph" sounds and prefer the single N
Edmund Atlas- 7.5, don't like the names much individually but they're so lovely together
Victor Cyril- 7, same as Edmund Atlas
Albert Ferdinand- 8, Ferdinand Albert would be higher- they go great together but Albert feels a bit clunky to me and I like Ferdinand much more!
I voted for Victor Cyril, just because I'm not really a fan of either of these names.
My top 5 from your list are
1. Leopold Darcy
2. Frederick Archer
3. Edmund Atlas
4. Darwin Elliot
5. Crispin Avery
1. Victor Cyril
2. Alistair Henry (love Henry but dislike Alistair)
3. Percival Julius
Thanks for all of the opinions guys! I think in the end, I will change the middle name for Darwin (Elliot feels sort of flimsy) and completely cut Pervical Julius. Neither name are really doing it for me.