Siblings with names starting with the same letter

[Tobermory]

Does it matter?
Cause any difficulties?

DD1 is Isobel but known to most as Bella. DH's favourite name should DC2 be a girl is Imogen. I'm struggling to decide if they are too close.

I know a Toby and Thomas which I think is lovely, if you like it go for it, Isobel and Imogen sound great, only issue I can think of is nightmare for post in the future!

Yes I had thought about post and their birthdays are likely to be v close... 10 days if DC2 arrives on Due date!

Isobel and Imogen are a bit too close for my liking. Same initial and same number of syllables - would you consider something like Iris?

My brother and I had the same first initial, but it's a bit different with boy/girl sibs - less easily confused. Post was a bit of an annoyance but nothing too major.