It is hard to say.Out of interest, would this arrangement typically achieve a lower impedance than a rod?
I noticed section 702 mentioned 20 ohms earlier.
(Appreciating this thread btw)
Low impedance (i.e. the ability to pull down a CPC with significant diverted neutral current) needs a combination of lots of contact with conductive soil. Generally to get reliable conductive soil you need to go deep where the moisture level is there all-year and it is not likely to frost and go high-impedance.
So it is quite possible to have a mesh a modest depth under dry-ish soil that is medium impedance but great at avoiding a voltage difference, but not as good in terms of earthing as, say, a 2.4m rod driven down to where the soil is damp.
There are various approximations that can be used to compute the impedance of an earthing rod or wire, but they are directly dependent on soil resistivity, and that parameter can vary from 10 ohm.m to 1000 ohm.m or more (i.e. 100:1 range).