Redefine how you classify the "action" of the rod Steve. To say "med" or "med light" doesn't mean much for cranks if the rod still bends in the last 1/3 of the blank. To really improve the hook ratio when using cranks, you've GOT to get that true parabolic action where the bend is pretty consistent from just in front of the handle all the way to the tip. If the backbone of the rod is still in the first 2/3 of the blank, you'll still not get that improved performance. For years that action was relegated to fiberglass, but recently blank manufacturers have been able to reproduce this action in high modulous graphite. They still feel like a buggy whip, but they're lighter.
Lighter lines will improve the action of any bait, but it's more evident in cranks.