I wouldn't say his names were more common than yours - I know of one of each on his list, and 5 out of 7 on your list.
Matilda Rose nn Tilly - pretty but very common lately Tabitha - ditto Madison Isla - I know of 3 Madisons! Freya - pretty but also quite common Alexa nn Lexi - I know of an Alexa, an Alexis and a Lexi. Seraphina - this is pretty and unusual, my favourite on your list. Emerson Rose - this seems quite an American name to me, more surnamey than firstnamey and quite masculine.
If you want some more suggestions, how about Fleur, Arabella, Jessamy, Rumer, Susannah, Eloise?
Just find something you both like. IME it's always difficult and pretty tense. Come up with a shortlist and decide when she's here. I'm pretty sure you'll get the casting vote after him seeing produce the child.
we've got a boy Emerson round our way. I also find you names to be ones that are currently fashionable. Tabitha id probably my favourite. Chloe is gorgeous.