I know this sounds silly, but would equal amounts of onion powder, and garlic powder give the equal same test perception? What if it is a super, super, super garlic powder? Really.?
Your welcome for posting the pics, I just wanted to make sure the pizza s.w.a.t. team wasn't following me.

Not in my experience..No...the garlic wins, but if onion extracts were used then it's a resoudning Yes.
If toasted deydrated onion or onion powdered was used then the answer is also Yes, but usually the ingredients will list if it's toasted.
I have only seen McCormick food service spices in Modern Shakeys.
Also I wanted to mention that when I visited Shakey's in Southern California, the cornmeal was also IN the dough. I tore the layers apart and took some pics, but they tuned out bit grainy. But I could post them if you guys thnk it will help.
I was not happy with ANY of the food I had there, so it may not be the best example.
Hope this helps.