When talking about shooting at foam targets or 3d targets , then yes , because of shaft diameter , the nod goes to carbons for penetration.

When we're talking about hunting it's a whole different ball game. That same shaft , wether small diameter carbon or larger diameter aluminum , now has a razor sharp broadhead on the front opening a path for that shaft , eliminating the diameter (path of least resistance) difference.

I've seen some major penetration differences between fast carbons and slower aluminums on hogs and the nod always went to the aluminums.

I personally shoot both , but I feel too many people today are steered away from aluminums for what I consider to be b.s. reasons.