I would strongly advise against using mains PE for lightning grounding.
Instead it should be a standalone and a dedicated lightning strike protection system.
We have these on off-grid data systems along with a system ground, consisting of lighter cabling to a single 2m earth rod.
The lightning protection system is much more robust and entirely separate of the system earth.
2x 2m earth pegs, 2m apart and 2m from system ground.
Lightning rod is 2m of copper coated steel extending 1.5m min above any part of the system.
All joints use heavy crimped lug connectors to heavy Galv or stainless fixtures wired with 16mm2 cable.....