No, they are not too close as middle names. As first names yes, definitely! I much prefer
Eleanor and I also like
Eleonora,
Elaine and
Leonor.
Helena seems to be a name everyone likes but hardly anyone uses :P I don't like how it starts with hell and in general I think it is overrated. Sure, it's a classic but it actually doesn't have the most attractive sound when you say it out loud. It is also kind of dark sounding,
Eleanor sound friendly and approachable.