Do all the 'balls' fit in the bowls?
Only for a given value of "fit".

Both of these pieces are part of set 70156-1, Legends of Chima "Fire vs. Ice".  On the front of the box, you can clearly see the blue ball 'sitting in' or resting on top of the white bowl, in front of the orange vehicle on the left.  It does not sit snugly inside.