I mean that I wouldn't use the names in a sibset if you'd name the other siblings like
Robert and
Natasha, but only if it's a "theme", if you want to give all your children a name starting with an "E". Then I'd find them cute together.
OR you'd have twins. Generally, I'm against giving twins names that are too similar, but to me, that would be
George and
Georgette or
Jaden and
Jade.
Esme and
Eden both have four letters and start with an "E", but they are not similar in the way I don't like.
So, I think
Esme and
Eden go well together in the two cases, not in a regular sibset.