Consistency is key, so I agree with establishing a pretty strict routine.
If your husband has trouble sticking to the routine or the timing, set alarms in his phone for each step and the time it should happen. I don’t have ADHD and I use a lot of alarms because I get caught up in other things. This app could help as well, and get your child started on following routines:
ADDitude Community Moderator, Parenting ADHD Trainer & Author, Mom to teen w/ ADHD, LDs, and autism