If you couldn't lay out a sprinkler system using a plumbing diagram and pressure loss charts and tables, then there would be no charts at all. You might have to get into advanced calculus or other esoteric mathematics. But we do use charts and tables, and we get results we can work with. If you have concerns about surges and water hammer, those are approached without looking at pressure losses. Instead, you are making separate calculations involving water velocity and pipe length and valve closing time. You are looking at reducing pipe sizes in a zone lateral, as you proceed from head to head.