Unfortunately its either an Iveco Daily or a 4×4!
I need to tow a 3000kg horse trailer, including across grass every now and then, even with the Iveco I have to downrate the trailer to 2800kg to stay legal unless I find a rare twin wheel version.
The Iveco is the only van that can tow 2800kg apart from certain Transits which are hard to find, and rear wheel drive is essential as I’d get stuck on wet tarmac hills otherwise.
A 4×4 will just sit there unused most of the time, at least the van can be converted to a campervan. (something I’ve been planning for four years!) Also its wider than a Sprinter/Transit which means I can have a sideways bed and therefore a shorter van. Its a 2.3 rather than the older 2.8 engine so hopefully mpg will be a bit better than you experienced.