@Oliver131313 depends if you want to sample 6 distinct variables with the same prior or 2 distinct variabls that are used in 6 places. It’s a completely different model.
It’s the difference between np.random.beta([1, 1, 1, 1, 1, 1], [3, 3, 3, 3, 6, 6], size=(6,)) and np.random.beta([1, 1], [3, 6], size=(2,))[0, 0, 0, 0, 1, 1]
The tip box in this section touches on this: Distribution Dimensionality — PyMC 5.1.2 documentation