I'd rather have Valaika everyday at 2B. Sanchez and Alberto platooned at 3B. Valaika had a 791 OPS in 2020 and I think it was mostly because he finally got to play everyday. His best position is 2B.
Alberto had shoulder surgery in 2017 and his arm showed it in 2019 but his arm looked stronger in 2020. His bat offers a lot vs lefties and he would be average at 3B defensively. Sanchez did pretty well vs righties in 2017 and 2018. He is not known for his bat but he can play a good 3B.
I think the right price for Alberto is around 2M and for Sanchez between 3m and 3.5m. I am sure their agents will disagree. Its going to be interesting to see if Elias can make deals with them before the non tender date. I don't think he will go to arbitration with either one.