As soon as we start applying anthropomorphism I am lost. Two of the three perfections I hear about are formless. My version of Siva is like Nataraja, very thin, a body of light, and constantly shifting to the rhythms of the universe.
So I think it is two different things, not that it matters.
Have either of you ever been to a Siva temple? Maybe if you went to one you'd know if it was the same or not.
I have seen Shiva in more of a meditative pose in the temples I've seen. Of course, since I am a Vaisnavite, I will see Shiva in a different outlook than a monist. I usually do not see Shiva as formless, so maybe that is why me and mystic have different ideas.