This is what confuses me, "Sizes of pipes and fittings and valves affect pressure losses, and pressure losses depend on the amount of flow.", if you have two different designs based on the exact same amount of flow, why change the size of mainline pipe, fitting, valves, etc, since as you say it affects pressure loss.
This was based on 60 psi at 14 gpm.
Rainbird;
5 zones with one being drip irrigation,
all 4" pop ups with drip irrigation being all drip-line.
Toro
6 zones with 2 being drip irrigation mixed in with lawn.
62 heads, 5', 8", 12" both pop ups and rotor.
Drip Irrigation has both adjustable flow stream emitters, flow bubblers, hose emitters.
In conclusion, I believe I'll just place a partial order this afternoon based on what I'm sure about.
Thanks for your help Wet_Boots and I apologize for my tone due to my frustration.