I feel like [name]Alexander[/name] is on a completely different plane than [name]Kieran[/name]
With brother [name]Cian[/name] or [name]Ciaran[/name] I prefer [name]Xander[/name] I suppose since it feels more unique.
From your list I like [name]Xander[/name] [name]Rhys[/name] and [name]Kian[/name] [name]Lucas[/name].
I think [name]Keiran[/name] and [name]Rhys[/name] go together the best for brothers out of all your name choices. What about [name]Keiran[/name] [name]Xavier[/name] and [name]Rhys[/name] [name]Alexander[/name]?
[name]Cian[/name] [name]Rhys[/name] is my favorite. I like it spelled with a K best. [name]Kai[/name] [name]Alexander[/name] and [name]Kai[/name] [name]Lucas[/name] are my next favorites. I think [name]Kian[/name] and [name]Kai[/name] are much too close though. [name]How[/name] about [name]Kian[/name] [name]Rhys[/name] and [name]Luca[/name] [name]Kai[/name]?
I think all of your combos flow well with the exception of [name]Ciaran[/name] [name]Xavier[/name] and [name]Ciaran[/name] [name]Rhys[/name] (tongue twisters). Personally, I would only use [name]Xander[/name] as a nn for [name]Alexander[/name] as it’s a relatively modern invention and very trendy. Although popular, [name]Alexander[/name] has more history to back it up and for that reason it’s quite timeless. I prefer the original Irish spellings of [name]Cian[/name] and [name]Ciaran[/name]. Yes, you may have to correct people but some names are just worth the trouble in my opinion. [name]Kian[/name] and [name]Kieran[/name] just don’t hold the same appeal for me and they lose some of their Irishness with these Anglicized spellings.
Possible Twin Combos
[name]Alexander[/name] [name]Rhys[/name] and [name]Ciaran[/name] [name]Lucas[/name] - with the nn [name]Xander[/name]
[name]Cian[/name] [name]Rhys[/name] and [name]Kai[/name] [name]Lucas[/name] (if you don’t mind the similarity of sound with the two names)
[name]Cian[/name] [name]Xavier[/name] and [name]Kai[/name] [name]Alexander[/name] (the brothers would share middle names ending in “er”. A subtle connection).
From this list, for twins I would choose [name]Alexander[/name] ([name]Xander[/name]) [name]Kai[/name] and [name]Ciaran[/name] [name]Rhys[/name]. Cool! I prefer [name]Xander[/name] [name]Kai[/name] and [name]Ciaran[/name] [name]Rhys[/name] but agree that stylistically [name]Xander[/name] may be a bit trendy.
My second choices would be [name]Xander[/name] [name]Kai[/name] and [name]Cian[/name] [name]Xavier[/name]. You could even change the spelling–[name]Xander[/name] [name]Cai[/name] and [name]Cian[/name] [name]Xavier[/name]–so they’d share reverse initials! That might be too cutesy for your taste, though.
Best wishes!
[name]Cian[/name] and [name]Rhys[/name]! [name]Both[/name] names are short, strong, Celtic, 4 letters, and perfect. I don’t care for [name]Sanders[/name], but [name]Alexander[/name] and [name]Xavier[/name] make nice middles. [name]Don[/name]'t worry about pronuciation issues. You only need to tell pwople once ans both names are so worth it. Good luck!
[name]Just[/name] about all of those combinations are nice. I definitely support using the full name of [name]Alexander[/name] instead of just [name]Xander[/name], and sticking with the traditional spellings of [name]Cian[/name] and [name]Ciaran[/name].