Which name do you prefer for #2?

Working on options for baby #2. Child #1 is [name_f]Elspeth[/name_f], who has many nicknames but most commonly [name_f]Elsie[/name_f]. [name_u]Baby[/name_u] would go by full name as well as nickname. Middle name non-negotiable.

[name_m]Theodore[/name_m] [name_u]Leigh[/name_u] (nn. [name_u]Theo[/name_u])

OR

[name_m]Archer[/name_m] [name_u]Leigh[/name_u] (nn.[name_m]Archie[/name_m])

Which do you prefer and why?

I prefer [name_m]Archer[/name_m] ([name_m]Archie[/name_m]) [name_u]Leigh[/name_u]
[name_f]Elspeth[/name_f], at least in the US, is very rare, and [name_m]Archer[/name_m] is way less popular than [name_m]Theodore[/name_m]
Also, [name_m]Archie[/name_m] and [name_f]Elsie[/name_f] sound really nice together

[name_m]Archer[/name_m], definitely