Correct, but it goes deeper than just the building components. In the US you have to go through an entire military procurement process within each iteration loop. So you design a weapon, then try to sell it to the military, but just the process of demonstrating it and selling it to the military takes a long time and costs money. If you fail you can go back to the drawing board, but each iteration loop is probably a year minimum. And if you are successful now you have to set up and scale production. Get ready for years of environmental reviews and lawsuits.
In Ukraine the military will take any drone they can get their hands on, so all you have to do is build a drone, give a bunch of them to the army to try out on the Russians, and within a week they will tell you if it works or not. So your design iteration loop is probably weeks. If you are successful, the time between hearing the general say "give me 1 million" and when the bulldozers start clearing the factory site is probably measured in days.