Another idea to bring in non armored villains like Blizzard, Whirlwind, Firebrand and Earthmover is to go the dtv Invincible Iron Man movie route. Have Mandarin control them, call them the Elementals
and update them to kinda look like this.
Or just have Hammer get out of jail, seek revenge on Pepper and use them.
Though having too many villains usually always ruins a movie, so just use two of them or so.
Iron Man Three - May 3, 2013
Thor: The Dark World - November 8, 2013
Captain America: The Winter Soldier - April 4, 2014
Guardians of the Galaxy - August 1, 2014
The Avengers 2 - May 1, 2015
Iron Man will return