The LCH is not for the Himalayas, but for stopping tanks. Chopper gun ships are tank killers.I think the point we keep forgetting is the goal for which the LCH was built. LCH was built with the explicit purpose of warfighting in the himalayas. This is something no other helicopters can accomplish with such grace. What is the use of a huge weapons loadout, when you cannot reach the theatre with a reasonable loadout?
The fact that they can operate in hi-altitute is an advantage.
BTW, who says the M-24/ 35 cannot be used in mountains. The Soviets used them to good effect in Afghanistan till the Stinger missiles changed the game.