Take into account wind, the longer throws will be more affected by wind, as the shorter ones would not, making your cross over patterns using the longer throws less effected on a windy day, just a thought.
it is all perfect on paper until you face the reality of water flow and pressure, unless you have some exceptionnel water pressure service at the source, you will never be able to supply all these sprinkler heads with constant pressure or flow. most residential areas have 50PSI, and most sprinklers in the market are not designed to be used according to the reality of residential water supply.
He's obviously just educating people on how to evolve a good design of a sprinkler system given a set of heads you know you are ABLE to use - clearly, to be thorough, the first step is find out what your flow/pressure limits are and factor that into your design process. This design process obviously assumes that you have the flow rate and pressure to accommodate these specific heads he is referring to. Also, lower flows/pressure can often be accommodated by increasing number of zones. What's your solution?
Generally, a sprinkler puts down less water on the farther reaches of its throw than in the arc closer to the sprinkler head. Research head to head coverage.
