Iraqis going to the M-16/M-4 means that they want an army of shooters, not sprayers.
The problem with the M-16 has been the gas system - direct impingement. It gets hot and dirty and needs regular cleaning. There are ways to mitigate - by using a gas piston system. Bushmaster, Patriot Ordnance and one other company makes drop-in uppers. Stays cool, minimal maintenance.
I have shot both .223 AK & AR... both work...
my AK did not jam, my friends LMT M4 did
Heckler and Koch make the 416.