As it is actually mentioned from the spell’s description, Hypnotic Pattern does place a charm about the affected creatures. You would not have benefit on attacks from incapacitated targets. Plus they even now make conserving throws as ordinary. These are clarifications on how the incapacitated situation (PHB 290) functions in https://patron-hipnotico98641.blogkoo.com/the-patron-hipnotico-diaries-53969904