Campagnolo uses a DIFFERENT SLOPE on the spindle flats than Shimano, (or most any other company). DO NOT USE Campy cranks with any other brand unless the BB/Spindle has been designed specifically for Campy, for example Phil Wood makes BBs designed for Campy. If you use Campy cranks with another brand BB/Spindle you may PERMANENTLY damage the cranks, rendering them useless except for "art displays". NO KIDDING, I've had first hand professional experience with this problem, the customer had to replace his crank arms, (but did save the chain rings).
Remember, Campy was in business long before S******* or most any one else around now, S******* introduced planned obsolesence to the cycling world, could have designed their stuff to be compatible with Campy, even though they "copied" Campy for a long time, and their claim to fame was making fishing reels before they got into cycling, maybe that's why their stuff is so complicated.
Ride Right
Pat