It's sad to see that you guys misuse iruka with naruto.
https://puu.sh/qUIGz/026b1e88d2.png

this is an example set up. Before you put in any ninja besides from main character in your line up, drop in naruto first and put iruka on your team last after you place naruto. Also make sure Iruka is completely below naruto and on the last row. That way Naruto will summon his clones first and then iruka will shield them along with the ninja.

You're welcome