Assuming you mean Heinlein's story "They", a possibility is "[The Dark Side][1]".  I think one of your other stories (the one about a man who is cursed to have water stay away from him) is "[Trouble with Water][2]" by H. L. Gold.  Both stories appear in this collection.

Edit: - - - - - -

Many thanks to [user14111][3] who volunteered the info that "Yero" appears in the story "[Mistake Inside][4]" by James Blish, which also is in "The Dark Side" collection.

This would appear fairly conclusive that the answer is "The Dark Side".

End Edit: - - - -

The two potentially identified stories also appeared together in these collections:

 [Les meilleurs récits de Unknown][5]

 [Unknown Worlds: Tales from Beyond][6]


  [1]: http://www.isfdb.org/cgi-bin/pl.cgi?270838
  [2]: https://books.google.com/books?id=Jh97v3zeKc0C&pg=PA145&lpg=PA145&dq=trouble%20with%20water%20hl%20gold&source=bl&ots=PgtZVw_G8Q&sig=JFMmMilAcGgJd5gaM6a1_3vpunE&hl=en&sa=X&ved=0ahUKEwi87bLavcrTAhWY2YMKHQq-CNMQ6AEIPjAF#v=onepage&q=trouble%20with%20water%20hl%20gold&f=false
  [3]: https://scifi.stackexchange.com/users/14111/user14111
  [4]: http://www.isfdb.org/cgi-bin/title.cgi?69751
  [5]: http://www.isfdb.org/cgi-bin/pl.cgi?367483
  [6]: http://www.isfdb.org/cgi-bin/pl.cgi?52878