Well, you gotta remember that when you drop them, the shock load is much higher than the weight of the actual wood itself.
It really depends upon how far it drops before the rigging system catches up and stops fall and how it is rigged.
So while ghe green weight chart may say 2K, you may be hitting the rigging hardware with 10 times that load.
Also, do not overlook areas such as knots in your line, which will reduce the load capacity it can safely handle.
Check out software to help you here:
Rigging Software v 1.0 : SherrillTree Tree Care Equipment