Despite thousands of advisors and instructors from Iran and NATO coming into Iraq to train or retrain Iraqi troops the process always takes more time than expected. The most difficult unforeseen obstacles are problems with language differences and complications related to coordination. Even the Iranians need translators for most of their trainers. Only a few percent of Iranians are Arabs and speak Arabic, although many other Iranians speak it because they do business with Arab countries. So most instruction is via a translator, which diminishes its effectiveness somewhat. What is being taught is specific skills that even combat experienced Iraqi militiamen may not know. This stuff is useful.
Another complication is scheduling the training. The Iraqis are notoriously unreliable when it comes to meeting deadlines. If the trainers and facilities are ready but the Iraqi trainees don’t show up on time, the trainers cannot keep to the schedule they had worked out. When the training program does not produce the number of trained troops promised the Iraqis will blame the foreigners, ignoring the fact that it was Iraqis who delayed things. That makes sense to Iraqis, who believe that foreigners, especially from the West, have some kind of magical powers to deal with problems all Iraqis have to put up with constantly.
There are other scheduling problems. For example the Kurds have a lot of troops in combat who they want to get additional training, especially on new weapons or equipment. The Kurdish troops are scheduled for this training during times that units are pulled out of front line for some rest and an opportunity to see their families. Typically a few days of training is included, usually before the platoons or companies return to the front line. Since these troops are in a combat zone, they do not always get their scheduled leave and training time because ISIL decides to act up and leaves are delayed until things settle down. While such delays are understandable, they do trash the optimistic training schedules included in the press releases.