It sounds like OP is happy with the set up and I don't see where control or financial abuse comes in here based on what she has said. It's basically just extending what a lot of couples do (ie pooling finances) to the parents as well.
Regarding your actual question op, I'd tell Dh that:
- All of you adults agreed to this set up but the kids haven't. You can't decide how they deal with their finances.
- Kids learn several things from having their own money:
A) how to budget and account for things
B) to value money (and things!!!) And how difficult it is to earn it and to save it
C) sense of responsibility
D) how to be generous and to share. They are not being generous or sharing if the money doesn't really belong to them in the first place or they don't have full control over it
E) to keep it safe
G) to value hard work
H) to understand your privilege of having money and not living in poverty
There are so many things that having your own money can teach you.
- Your parents want that the money they give your kids is exclusively their money for their own use
I come from an Indian family and my parents very much take the view that all their money is also my money (not the other way round though...). As a child I did get pocket money officially but they mostly forgot to give it to me and I forgot to ask them. If I wanted change I took it from a little common box and if I wanted more than that they just gave it to me without questions.
I got my first job when I was 15 and I really, really enjoyed earning my own money and budgeting with it. I stopped taking money from my parents (I don't think they noticed) and looked forward every month to what I could buy.
Ever since I've moved out (I work and I'm married with kids) my parents have continued stuffing money down my throat and I really resent it. I want to be proud of the money I earn and contribute. I still am generous with it. If my parents ever needed money or one of my siblings I'd freely give it to them (and they to me) and we don't keep count of who has paid for what (ie rather now everyone wants to be the one to pay as we don't want to take advantage of our loved ones) so I get not making that difference between what is ours and theirs when it comes to family.
For young children, however, j think having their own money is an invaluable lesson.
Also, your husband has to learn to see his kids as individuals who might want to do things differently to him. It's not the point of your post but it's something to be wary of in the future.
From what I've seen in India, us Indians we really struggle with letting our kids (or even parents) grow as individuals and to differentiate from the parents. (And Money is crucial in being independent).
So this might be a good learning experience for your husband in letting his kids do things differently. Your kids are still young but this is a sticking point with many Indian families I know (both in India and abroad), including my own and dh's.