Definitely - both players are mediocre. But honestly, Pelle has some interest attributes. He is actually very good distributor for being a CF. He could potentially create a lot of space, and be useful in certain matches. He would cost 10 million euro, while you could sell Zaza for 25-30 million to the EPL.
If we kept Morata, a strike force of Mandzukic, Morata, Dybala, Pelle isn't bad. If we sell Morata, we will need to buy a striker who is more quick. Pelle, Mandzukic w/o a Morata replacement is asking to be pinned by the likes of Bayern type pressing teams.
I'm only advocating selling if the price is significantly above market. If a team offers £20-25+ for Zaza, it is a no-brainer.