Actially, Iranian missile engineers has surpassed their North Korean counterparts.But looking North Korean satellite launch attempts, they used a satellite launcher that looks nothing like what we see in Iran. It was completely different, much bigger and heavier, and with three stages.
The Sajjil solid propellant missile is very difficult to guide and control. Iranian engineers are overcoming those problems by using a modified Shahab 3 guidance system with the the help of the N Koreans whom helped design the Shahab based on their No Dong 1.
You’re right about the launchers, that’s not something the N Koreans were ever focused on. Iran correctly saw how elusive Saddam’s SCUD launchers were and those that made it to Syria likely ended up in Iran. They would be hard to find and degrade if we ever have to go after them.