Horsepower limit for out of the box Edelbrock RPM heads

"You're gonna be mashing that thing all the time at different RPMs and you want it to pull hard every time," or something along those lines is what he said.
EXACTLY! You need smooth, wide torque to make the brain-to-foot-to-rear wheel control of the torque on the rear tires wholly predictable so it becomes a muscle-memory control for the driver. Plus to make sure you always have a gear that will work, whatever the speed. That's is all to get the right slip on the wheels to throttle steer, as well as to get a good launch out of every corner. You eventually run out of torque at the higher speeds, simply due to the lower trannie gear ratios, and have to change your driving style. That is where a big block's torque would step in, and be of use on the higher speed, wider open courses.
And if I can be forgiven..... this all becomes 'moreso' in rallying, where every one of the thousands of corners in an event are different.

It becomes a quest for car control with the throttle over raw power, and you don't have that throttle control if you don't have adequate torque at the drive wheels in all conditions. So you either build for a wide torque band, or put in a 6, 7, or 8 speed trannie with electronic shifters, like the top end rally cars of today have.

Once again... application drives the engine design.