I tune street cars for the track, and there are always several tradeoffs to be made when setting up a vehicle.
The primary knobs are Torque vs. Weight, HP vs. Drag, and Money (vs. Poorness).
A heavier vehicle will always require more torque to accelerate it from a standing start or up a hill. Adding weight in the form of armor or other accessories only makes a bigger job for the stock engine to accerate the truck. And for any given engine, you will always have to push farther into the throttle in a heavy vehicle to get things rolling. (Incidentally, increasing the inertial mass of the wheels and tires also requires more torque to move things forward, and increasing the tire diameter effectively raises the final drive ratio, which also doesn't help acceleration.)
At highway speeds and above, drag is the enemy; drag is the product of coefficient of drag (Cd) times the effective frontal area. So increased tire sizes, lifting, and any hardware that increases the frontal profile of the vehicle or increases the drag coefficient will require more HP to move it through the air at a given speed.
The above two challenges can always be compensated for by spending More Money. That's why the factory hot-rodded trucks and the top-line European SUVs have more powerful engines, and are substatially more expensive than the standard models.
Having said all that, I didn't buy the T4R to race. And I didn't want to spend $10k+ more to buy it. It's got a heavy BOF so I can take it through terrain too rugged for a uni-body crossover, as well as pull a travel trailer or track car. I don't plan on winning any races doing either. And I want it to last at least 200k miles.
Incidentally, I agree with nw-hunter. Almost all modern cars have a "drive-by-wire throttle", and actually have a program that decides how much to open the throttle for a given pedal movement. Although some manufacturers and aftermarket tuners remap the pedal-to-throttle map in the engine ECU to get quicker "throttle response", this is usually to compensate for/mask a powerplant that is perceived as underpowered for its target audience; this is achieved by opening the throttle body faster for a smaller amount of pedal movement. It makes the vehicle seem faster.
Ironically, in race cars, it is more important to have a linear throttle mapping that allows a good range of engine control/sensitivity when the vehicle is at the limits of tire grip and/or traction. I'd guess that that would also be a desireable trait for a slow-speed off-road vehicle as well...
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