I tow something similar to the Conqueror. Mine is about 2000lbs. It's a non-issue, other than the obvious standard towing concerns. The truck doesn't have a lot of power, so you gotta expect to drive slower, with lots of downshifting on hills. It's not as stable as say... a Suburban due to the wheelbase. But then the steering and braking is so much better on a Disco than it's contemporaries, that helps. The D2 also has a generously sized transmission cooler.
In my opinion, whoever told you that (and I can imagine...) is wrong, it's completely fine.