There are so many different groups under the Sadrist current SolidWood. As many as half of them don’t even take Sadr’s orders and are either working with the US or working with Iran.
Well yes, but the one at the meeting apparently were loyalists to Moqtada, if the statement of the speaker is accurate.
Anyway I think loyalists of Moqtada al Sadr should be described as something like “Moqtadists”, since the name “Sadrists” doesn’t refer to him at all, but to his father. As you said there are Sadrists not under his command.