Well, that's part of the trouble. The AEV Brute is a novelty aftermarket conversion, which while is really cool (though I still would rather have the previous TJ-based Brute), has none of the engineering support of an OEM vehicle. So, yeah, its a pickup. But AEV isn't in a position to re-rate the towing capacity compared to the Wrangler as it left Toledo. Also, keep in mind that this is still a midsize pickup. So, while 3500lb is still weak (my '98 Explorer V8 is rated for 6500), expecting to be able to haul large livestock trailers isn't realistic either.
FWIW, aftermarket crew-cab pickup conversions must be all the rage these days. I saw this at the Ford Nationals event at Carlisle back in June:
The company was selling conversion kits, extended tubs, etc. The frame had a healthy extension ahead of the rear axle. Also FWIW, it seems like Jeep has gotten a lot of mileage out of that Gladiator-style front clip that they used on the above M715 concept:
I'm in particular a fan of this one, as I'm a big fan of the Cherokee Chief and other 2-door SJ models. What's cool is that all of these vehicles are built from the existing Wrangler platform. In fact, if you look past the nose sheet metal, there's quite a bit of Wrangler bodywork in them. All of these have been built for various years' Easter Safari as concepts. And while we're at it, here's one more that takes the modified KJ to another level, especially cool if you're at all familiar with Jeep Forward Control trucks: