It is more of a problem when you go between different manufacturers. But the basics are still there. Fuel has to go from a tank to an engine. There is going to be a lump of metal spinning in a magnetic field with wires leading off who knows where. There are some pumps pressurizing fluid. There's bleed air. And there are some fire extinguishers. Saab may call stuff by different names and the numbers will be different but you go deep enough the ideas are the same.