Most SMP components are wrappers for web service methods. The likely case is that there are 2 components for 2 different signatures of the MoveItem method.
For example, there could be a MoveItem method that takes a string parameter and a MoveItem method that takes a Guid parameter. Right-click help on the component will at the very least show you the types expected for input and the types output (if any). Thus, the need for 2 components. And to simplify things, we just slap a number on the end to deviate from the first component.
If theres no documentation for any components you look for, and it's a wrapper for a web service method on the SMP, check the SMP documentation - the component basically does exactly the same thing as the method.