Well if it's as people say SAM is most likely cast-slash-slash or slash-slash-cast, meaning that the charge up is either the start of a combo or the end of a combo. Funny enough saying it like that makes me feel like SAM and RDM will almost play the same in the sense they have a no cast combo and then casting combos, but RDM might be more flexible in when they focus on the casting where SAM has a consistent casting ability with each opener or closer.