I think your set sounds thoroughly appropriate, and likely to be at least partly guided by your children which is one of the beauties of out of school activities.
It's prompted me to think back to not just what my own children were doing at that age, but also what my sister and I did.
Me - ballet (various groups, predominantly as a form of physical therapy), music group from preschool age, swimming lessons from 6 (I'd had ear trouble). Then we added violin lessons. After I gave up ballet age 8 (physically reached my limits), my mother said she could stretch to me having piano lessons (I'd done a bit on my own). Age 10 we joined a youth orchestra. Swimming (in season) continued most years, at secondary I tried to train at school when I could - not very good but enjoyed it. Music stayed dominant (also played recorders). I never felt we were doing tons of activities. Just remembered Girls Brigade as well (brownies/guides were harder to get to from where we lived).
My younger sister didn't start ballet till I stopped, then kept it up till the end of primary, though only once a week as with all the music it would have been hard to fit in more, and was decidedly unaffordable. Swimming and music she did pretty much the same as me, a lot of our violin we did together (till she pulled ahead of me at the age of 10).
With my own children; Swimming lessons and violin lessons started when they started school, roughly. Choir was added shortly after when the eldest asked. Other afterschool stuff like brownies or school-based clubs from 6. My youngest wanted to do lots of after school clubs from year 3 but we had to pull him out of them when he got too tired (summer birthday). Reduced to twice a week, and piano lessons after school. Violin lessons were at home with me by that stage. After that year both became choristers so extra activities were almost entirely school based, but physical activity was an important part of that.
I think at lower primary age, the important thing is to not fill evenings up so much that reading and homework can't be done. But if you don't need to have them in afterschool care there is actually plenty of time. And if an activity appears to be a waste of money it is the parent who decides to stop!