This thing is going round and round and round. Lets make it simple.
What is the XUV? It is a crossover. It is meant to be driven on road with occasional and mild offroading like unpaved routes, ruts, mud, etc.
What is the Storme? It is a good SUV in the 4x4 avatar. In 4x2, it still remains an SUV, minus the "good" part, means it wont be able to handle rough terrain as well as the 4x4, but of course.
What if I need a true blue off roader? I may buy a Gypsy, Gurkha, Mahindra Jeep, etc.
What if I need an SUV with occasional genuine off roading? I may buy the Storme 4x4.
What if my occasional off roading is limited to just some loose slush and mud? I may consider the XUV AWD.
What if I need an on-road car? I will consider the XUV 4x2 or the Storme 4x2 depending on my requirements.
Personally, I feel XUV is better on-road than the Storme and Storme is better off road than the XUV. Reason being I feel the XUV has a more balanced ride and handling combination.
For someone like Raja, Mr. Ranger, Guralla, etc. they may feel Storme is better both off and on road.