Fighting ISIS

ISIS has, it is reported, 30,000 fighters. The Iraqi army has 271,500 armed personnel according to Wikipedia, and 528,500 reserve personnel, It has a budget of $6.055 billion. The army is, or was trained by the Vinell Corporation, a privater military company, a subsidiary of the Noprthrop Gumman Corporation. A small insurgent group like ISIS should not be a threat to such a well endowed large army. What difference can New Zealand's modest and reluctant contribution make to the unequal fight against ISIS?