Let be: one verb or two? [closed]

Both are fine, as Barrie said. What may be making you question your own judgment here is the novelty of the locution or the fact that you are talking about X’s and Y’s. Under these circumstances, if you’re wondering about grammaticality, it is often useful to preserve the grammatical form while switching to more familiar words. If you ask whether the following are grammatical, the answer is (hopefully) an obvious “yes”:

Let Mary eat bread and John drink chocolate.

Let Mary eat bread and John, chocolate.

And, if they are grammatical, then so are the sentences you gave.