What are we using that says Urshela is an outstanding defensive 3B? I see it parroted all over TD, but just eyeballing his defensive stats I see average marks. The larger problem though, is that he hasn't hit for any power. Like none. His HR on the 15th was his first in over a month. The only palatable part of the 7 game triple slash you posted was his slugging, otherwise the rest was more of the same. Unless we're expecting him to double his career high in HRs, that slugging will slide back down too.
I think Sanchez just is what he is at this point; a decent power bat that will hit in the low .200s, strike out a ton, and be below average defensively. Basically, he's the catching version of Miguel Sano. If Jeffers wasn't scuffling at the plate, and Sanchez was't used so frequently as a DH, it'd be easier to ride the ups and downs.