I have 7 Children but my husband and I can only have 6 people on our apple account.

I need to figure out if I can add a second Apple ID onto my phone so that I can manage the rest of my children’s Apple ID’s/ iPads and IPhones, my kids range from age 22, down to 3months old. My husband has an android phone and I manage my children’s accounts but I am only able to have 5 out of 7 which is definitely not fair to my 10 & 11 year old who haven’t been able to get new apps because it’s so difficult to logout and login to another Apple ID on a different device to approve things. Not just that but I also already pay the 29.99 for Apple services and I’d have to pay another 29.99 to give the same services to the rest of my children. Is there any way around this!? Feel like I am being punished for having more children by Apple, if my husband also had an iPhone we could get only 3 kids Apple ids on a ur account? So can I add another Apple ID onto my phone to switch back and forth? That’s the only thing I can think of to try.