I think they are too similar. I don't think twins need to have similar names simply because they are twins. They should be considered individuals and named just like you would name any other siblings. We have had 3 sets of twins at our school with very confusing names. To top it off, they were all identical sets of twins. Here are the names:
Alyssa and
MelissaDeAnte and
DeAndreMario and Omarion