[name]Winston[/name] [name]Sage[/name] [name]Hugo[/name] - Though [name]Winston[/name] is not to my taste, I like this. It’s not as adventurous as your other combos though, so comparitively it seems a little plain. Not sure if that’s just because you’ve got it next to some really unusual names 
[name]Winston[/name] [name]Indio[/name] [name]George[/name] - [name]Indio[/name]? [name]Haven[/name]'t heard that before, it’s interesting
This is cute, but again seems quite plain to me. Maybe it’s just because I’m not a huge fan of [name]Winston[/name], it seems very heavy and dated to me.
[name]Sullivan[/name] [name]Hugo[/name] [name]Jupiter[/name] - I wish I could love [name]Sullivan[/name], it is quite handsome! [name]Just[/name] can’t get the Monsters Inc association out of my head. Still, this is goreous. I think it’s great with [name]Tobias[/name] and [name]Mabel[/name]. My only issue is [name]Jupiter[/name], as it’s very similar to [name]Juniper[/name]. I know you say these are set, but I think it would be just a little better if it was switched to [name]Sullivan[/name] [name]Hugo[/name] [name]Sage[/name]/[name]George[/name], that way it doesn’t overshadow your girls name.
[name]Thea[/name] [name]Catherine[/name] [name]Clover[/name]/[name]Cleo[/name] - I do adore this, but I think it would be nicer to avoid siblings sharing first initials. So for that reason, I’d give this a miss.
[name]Edith[/name] [name]Lucy[/name] [name]Cosima[/name] ([name]Edie[/name]) - Stylistically, this is perfect with [name]Mabel[/name] and [name]Tobias[/name], though I think [name]Edith[/name] would be a little predictable. That may not bother you though! [name]Cosima[/name] is gorgeous, and has the same lovely unique feel that [name]Rowley[/name] and [name]Juniper[/name] do, while [name]Lucy[/name] is more vintage classic like [name]Quentin[/name] and [name]Elsie[/name].
[name]Edith[/name] [name]Cordelia[/name] [name]Lucy[/name] ([name]Edie[/name]) - Very lovely, but I think I prefer [name]Cosima[/name] over [name]Cordelia[/name] in the potential sibling set. [name]Just[/name] doesn’t seem to fit as well.
[name]Jemima[/name] [name]Catherine[/name] [name]Clover[/name]/[name]Cleo[/name] - This is my favourite. It’s amazing with [name]Tobias[/name] and [name]Mabel[/name], and the middles are gorgeous. I’d go for [name]Cleo[/name] over [name]Clover[/name], it’s just that bit more spunky in my opinion.
Good luck, whatever you do! You have lovely taste