I can only imagine how glacial a 2.5 diesel P38 would be. Hell I hate the 3.0 TD6 motor they later put in the L322.
I had 4 38sbut never even thought of buying the 4.0 V8 as it was slow like a diesel tractor. The 4.6 V8 was just about reasonable. Not fast by any means but no slow either.
Slow poking about hills and off roading in the desert are two different beast where momentum is king and not torque.
Old small displacement diesels have no place in the desert.
As for the OP a 3.0 on a swb chassis should be alright.
3.0 lethargic? Really? Not trying to fight with you but the numbers seem respectable. In my country if you're engine is over 2.0 you're king of the world. The galloper power to weight ratio seems respectable to me.
From my country, a 2.0 turbo diesel will pull you anywhere you need to go. Most 4x4s are diesel. I had a 2.5 TD P38 and a 3.0 TD Colorado. Both manual. Both happily chugged their way up any hill I put them to. Both pulled any load I put to them too. And tbh they were both bought to be tow cars.
Hyundai Galloper in the days borrowed design and parts all from our favorite Pajero. A very lethargic 3.0 V6 which never really got the market here in a good way. But in South Africa it is king and lots of people love this machine. You should get it quite cheap here as there is no resale value for this.
Indeed it looks nice and awesome, and also off-road ready with the big tires, lift, roof rack, additional lights etc.
Just make sure that engine has a bit of life left and not clocked 300+ kms or engine shouldn't have some trin trin (bearing noise) of knocking (piston hitting) at high revs or doof doof blocked valve noise at low revs.
From the looks, it seems Pajero brother so I assume it's using many parts from Mitsu factory.
Is this 3.0 or 3.5? Check if its running 6G72 (3.0) or 6G74 (3.5) engine? If 6G72 you are still in luck to plonk clean engine in less than 4-5k. If 6G74 it's most potent engine but impossible to find it clean even for 7-10k.