actually this is a good buying guide for new amateur users (with some modifications). just plan a system like Jarvis and that’s the cheapest (best cost performance) plan than keeping buying low quality gears = waste of money.
some alternative gears may be
– instead of two D4’s, one D800/D610 or D700, plus one D7100,
– instead of two 5D3’s, one 5D3/6D, plus one 70D,
– Canon 24-70/2.8L2 and 70-200/2.8LIS2 instead of cheaper lenses,
– 50/1.4 (Sigma 35/1.4) instead of 35/1.4L,
– get the most robust tripod/head that you can carry first,
Started out doing photography at the age of 6 using an uncle's old 1940 kodak brownie box camera. At 15 years of age, I decided to buy my very own 1975 Praktica SLR camera. I now shoot with a Nikon D850. I do unpaid TFP and commercial paid work.