I can't "prove" it either and I wish there was a clear-cut, definitive means of doing so. Oh, and Cycloniac, thanks for digging that up....I actually forgot I had that in my thread.
To the OP:
You don't HAVE to marry yourself 100% to the scheme, but you have to ask yourself if what you want to do makes sense. You have to dig deeper into individual player ratings. You CAN run a zone scheme with a power back provided that either a) your O-line is decent in power block ratings or b) your RB has solid accel/agi ratings to complement his power skills.
This is the aspect of the game that gets overlooked a lot. You CAN get quite creative with schemes/playbooks/archetypes. Imagine Kingsbury's air raid-oriented playbook while running a vertical power scheme. If you have the right personnel, you can bludgeon opponents inside and then stretch them out horizontally with jet sweeps and touch passes. Once you suck them inside the numbers, you can hit them deep with your speedy receivers. For the majority of passes in that offense, you don't need great pass protection..so the air raid scheme itself doesn't really help (and it SUCKS on the ground because of the pass protection o-linemen).
Here is my number 1 suggestion. Start with a plan. Know exactly what it is you want to accomplish and HOW you want to accomplish it. Don't just 'paint by numbers' and max out percentages because that's what the game says to do - but really embrace the roleplay and design things in the image you want to adopt.