I see your problem. Anc < n*Anco is how the code tells us that the actual projected area can't exceed the theoretical for n anchors. The specific exception for multiple anchors is the n in n*Anco.
P.E.
Oratio imago animi.
Anc for ONE anchor can't be bigger than Anco - Anco is the ideal anchor breakout cone, and the Anc is the actual breakout area based on edge distance. Anc can be greater than Anco when you've got multiple anchors in a group located far enough from edge influences. You're right that Anc/Anco...
Check the governing building code. It will tell you which version of the code is applicable to your project. IBC 2006 specifies the 2000 version of the Aluminum Design Manual.
When doing your design, read through it the specification and commentary to get a feel for how it works. Then go right...
If you aren't specifying and designing the crane and rigging, don't make any mention of it. Otherwise, you'll end up on conference calls discussing whether your specifications allow this other crane, that leftover wire rope from the other job and how to bridge over the rain water conductor that...