If you are considering a new vertical antenna, instead of guesswork and copying somebody else's un-thought-out efforts, download program RADIAL_3 from website below.
The program assists with choosing an economic length and number of shallow-buried ground radials. It takes a new look at how radials work by considering them to be lossy, single-wire transmission lines, open-circuit at the other end.
RADIAL_3 is a self contained file, 55 kilibytes. Easy to use. No training needed. Download in a few seconds and run immediately.