Iron man in Diamond+?

Ive had no trouble grinding through ranked using a Combo of Iron man, Magneto, Cap, and wolverine, however upon hitting Diamond 3 ive suddenly been locked into only playing tank, due to the fact of Iron man's become ineffective with snipers being Too precise to avoid, enemies playing outside of Unibeam range, and tanks soaking up unibeam if i try to press for kills. Even with punisher+Hela banned i get Combo'd by Buckys and Hawkeye when im full hp being healed.

Any advice?