Ok, admittedly i have not read this 35 page thread yet and im just responding to the original prompt. Maybe some of this has been said.
But I'm an ASE Master Tech (with an additional hybrid-specific ase certification) who also has a strong interest in electric propulsion, has owned 5 hybrids, taken apart hybrid battery packs, powers his house on batteries when the sun isn't shining, and as an automotive instructor is about to start developing an EV/Hybrid specific curriculum for the community college i teach at.. blah blah blah i know stuff about high voltage propulsion.
I think EV tractors can/will penetrate easily into the SCUT/CUT markets because there's relatively short 'duty cycles' and less PTO use in those segments vs actual farming/agriculture production work. You basically don't need as much 'range'.
They certainly CAN perform in the other segments, but unless the tractors are built with some eye towards 'modular' or universal battery placement, wiring, controls, etc, they will be 'short timers' in tractor terms because batteries WILL degrade and cannot exactly be 'rebuilt' (the packs can, but not the cells themselves), and once technology inevitably marches on and those particular cells go out of production, unless it is easily replaced with whatever the currently available battery tech is, that whole tractor will be impractical to use for the work it was designed to do because it will be very difficult to repair it back to its original function without being able to duplicate the original battery architecture. They'll be 'orphans' due to lack of parts availability far sooner than we're used to.
I still own blue ryobi 18v tools, for example. That's only possible because Ryobi has made an unusual effort to stick to an 'old' battery form factor so that new batteries are backwards compatible with old tools. If tractor manufacturers don't do that, the tractors will be 'disposable' after the original batteries' cycle life is expended.
One thing i think would be very interesting but i dont know whether anyone's working on it, is hybrid tractors with batteries AND internal combustion engines. These would function like PHEVs or 'range extended EVs' do in the car world. They could be used purely on battery for as long as the batteries last, and then the combustion engine would kick in to serve as generator. They could also be made to have say 100hp on battery, but 150hp on battery+engine. They could also have a 'hold charge' mode like many hybrid cars do, where the engine runs to keep the battery full so you can switch to battery-only operation later in the day etc. You get around the 'range' restriction of batteries, AND gain a ton of efficiency vs pure ICE construction.
Another thing about using an engine as a generator instead of a 'traction engine' is that the engine doesn't have to be able to operate over wide range of speed and load, so it can be optimized for great power and efficiency within a narrower window. For example, Mazda hasn't been able to get their rotary engine to hit emissions targets or achieve good efficiency or durability as a traction engine but they CAN make it clean and efficient and long-lasting as a generator running in a narrow rpm and load range. So the engines used wouldn't need to be nearly as large as current ones but may still be able to provide the same power over time at greater efficiency.
And hybrids don't become as impractical to use as their batteries fade. For example, the 2007 Prius i used to own is now at 371k miles on its original battery pack, and it is still a totally usable car that just gets worse fuel economy than it used to because the gas engine runs more. But it will technically do all the same things it used to do, it just uses more fuel doing it, but still less than a non-hybrid equivalent from 2007.