1.) You are running A57, right?
2.) If you look in c:\WoS\Save\Evergreen you see the REAL savedHeroes folder, right?
3.) It has ALL your heroes in it, right?

In that case, you can safely delete the old-fashioned savedHeroes folder in c:\Wos\Worlds\Evegreen

Oh, and:

4.) You promise never to run a version earlier than A57 ever again and thereby shoot yourself in the foot and then come whining to me about it, right?

1. Yes.
2. Si.
3. Oui.
4. Aye-aye, cap'n!

(A little bit of culture, courtesy of Daine)

[Added]
Oh, and I was referring to mine own little world, but I deleted the EG and Aerianell duplicate saves, too. Free up some more space!