I'm afraid I have to disagree here, I'll talk about my own experience marshalling in the desert.
In beginner drives (especially first timers) we teach people about operating their 4WD vehicles (most don't know how to properly engage 4WD), the different options, the equipment they need, and how to start cruising in the sand easily, which actually can be done in virtually any 4WD/AWD cars there (provided the leader is aware of the car's limitation in his convoy), even KIA sportage should be able to navigate in and out without any drama. truck power is completely irrelevant there.
We don't push anything beyond that as desert driving requires practice.
Duster has enough grunt to cruise in the desert, actually more than enough with it's 2.0L 133hp engine (3.0L Pajero weights more than 2300Kg and barely makes 175hp, the duster 2.0L weighs around 1200Kg and makes around 133hp and 195Nm of torque.. one of my friends drove his 3.0L LWB Gen3 Pajero from complete newbie up to fast advanced drives.. the duster specs are on a real advantage here)
Engine power is not the problem as much as the front approach angle, which is no bad btw.. however it shouldn't be seriously challenged in beginner drives anyways.
so, a first timer in the desert should be comfortable to join my beginner level drive, have fun, and leave with his duster with no damage, and appreciate what this little 4WD car can do, and where it falls short.
an expert driver will be able to take the duster to much higher levels, while still respecting its physical limitations and avoid serious damage. that's why it would actually be still ok to take it to intermediate levels, once the driver gets better understanding of his duster, and how to navigate in the sand.
that's said, anyone who wants to take desert offroading seriously and to relatively high levels should choose something with more power and low gear for sure, duster would be fine for people who want to cruise in the desert/mountains/wadies, have relaxed fun, and reach a nice camp site, rather than drive in the big dunes and challenge other SUVs. basically what a beginner drive should be.