"inner monologue" exists whenever people have hopes, dreams, plans, etc--thats what humans being intentional agents mean. Sure, there is a spectrum: those whose monologue is so active during the wakeful time to those whose daily brief monologue is about what to say in tomorrow's scrum standup.
It seems more likely that a theory that bases being an intentional agent on the notion of an inner monologue is not the best model for what's happening.
