Best to find partner with same European roots?

[thisisafalsealias]

Wondering, is it best to find a partner with identical roots (etc you are french and british so you find one who is french and british too) or stick within general groups (mixed germanic vs mixed all vs pure irish) or is it just so long as they are European too youre good? Honestly I will probably have my own opinion but incase it is factually wrong Im interested what is generally accepted.