Proper grounding in extended outdoor networks

In addition to several other hats I do facilities work at a low budget but physically large outdoor venue. My professional data work has all been indoors (single site, no inter-building runs) so I'm a bit out of my depth here.

The site in question has multiple transformers but most of the network is powered by just one of them (the connection between the two is via F/UTP with shield connected at one end, and I haven't had a problem with it other than one direct strike on a power line). Most runs are around 80m, between switches ultimately powered from one electrical panel. The furthest powered switch is over 1km from the panel. After that, it's all POE, which gets us another few hundred meters with POE++.

Cable is gel-filled (nothing else survives out there, tho the ants seem to love it) direct burial F/UTP, which can be in conduit, buried, or aerial, depending on local conditions. I've been consistently connecting the shield at one end of the cable and not the other, using surge protectors at both ends (usually L-com), grounding to a separate ground rod NOT bonded to the power ground (where there's power). Switch cases are grounded to the same local ground system. They're all small, relatively inexpensive switches (ubiquiti 8 port POE for example) powered by external transformers, but I'm not sure if that isolates them effectively from the electrical ground or not.

I've read multiple sources on avoiding ground loops, how to properly ground lightning protection devices, etc. I've seen several posts recommending you ground the protector (and thus presumably the cable shield as well) via a low impedance path to the main grounding system. Which would be great if it weren't hundreds of meters away. That's clearly not an option. I haven't found much advice for situations where you've run power and data a km away from the panel.

So. Am I doing the right thing by bonding the cable shields at a single end, and grounding the surge protectors to separate ground rods? Or is that likely to make things worse due to earth potential differences from nearby lightning causing current to flow back through the equipment? Would I be better off connecting the surge protectors and cable shields to the electrical ground?

Fiber, unfortunately, is not an option at this point.