I love the nicknames of [name]Nate[/name] and [name]Rio[/name] for them. I never realized how similar they were until a few days ago though.
Is this a no no? And what about for twins? Too twinsie?
I wouldn’t do it for twins, but I don’t think it’s awful for just brothers. I’ve heard of brothers like [name]Michael[/name] and [name]Gabriel[/name], [name]David[/name] and [name]Daniel[/name], [name]Daniel[/name] and [name]Gabriel[/name], etc., which are just as matchy, imo. So I think [name]Gabriel[/name] and [name]Nathaniel[/name] would be fine, especially since the nns are so different. 
I don’t think they are too similar at all. [name]Gabriel[/name] and [name]Nathaniel[/name] have different sounds, despite their similar endings. I agree with ashthedreamer… the nicknames are different so they sound nice together.
I agree, I see nothing wrong at all with using both of them. [name]Even[/name] if you’re using them for twins. I adore [name]Gabriel[/name]!
[name]Love[/name] both names, I don’t think they are too similar to be weird. [name]Love[/name] the nicknames too!
I dont think they’re too similar. Especially if you would mostly be calling them by nicknames.
I really like [name]Nathaniel[/name] and [name]Gabriel[/name] together. Very handsome names!
I asked this very question on a different site a while ago because I loved both names. However, both are now only middle names for me.
I don’t think they are too close at all, obviously the same endings but at one point I had [name]Elijah[/name], [name]Micah[/name] and [name]Jonah[/name] on my list and I’d still use all three names so I don’t see [name]Nathaniel[/name] & [name]Gabriel[/name] as a problem.
Thanks so much for your input guys. 