Yes i believe Brees would be the same all world QB.
His 2 last seasons as a Charger where under Cameron and he made the pro bowl and had top 10 stats.
He actually won comeback player of the year under Cameron.
Pretty good coming back after a big injury TBH.
heck the Chargers just drafted his replacement after they feared he would never be able to play at a high level again.
Anyone that watched him play should see it tbh.
He has good mechanics.
He knows how to move around in the pocket like he has eyes in his back.
He can read defenses.
He can make pre snap adjustments.
He is pretty darn accurate with his ball placement and seems to know how to hit his receivers in stride.
Im actually quite impressed with how he mastered the offense and seems to be in full control.
He is not perfect in that system but he is the closest to it tbh.
His abilities speak for itself.
Heck when he signed with NO , he had to go to a new team , in a new city , with a new coach , new players , new coordinators, new scheme not to mention had to deal with the aftermaths of hurricane katrina.
He played lights out from the start which speaks volumes on how good he really is.
His talent and IQ would make him a top 10 QB in at least in any system other then the read option.
Same would go for Brady and Rodgers and Peyton.
They are simply just that good.
There are players that transcend scheme/system.