It's not (at least not for me) that I think Sangaré is amazing, though I think he is decent. My issue is that Luiz may or may not prove to be the Villa version, and even if he is the Villa version he can't play 60-odd games. I am a huge Domínguez fan, but he is still some way off being fit, let alone match fit.
I just don't want to get rid of Sangaré & then find ourselves 5 or 6 weeks down the line with a Luiz who is not yet up to speed, or is injured, or both, before Nico D is ready... leaving us with Yatesey as the only defensive midfield player just as we start the Europa Thu-Sun grind. Anderson is amazing, but he cannot play everywhere, every game, or both.
If the club think Nico D is closer than he appears from outside, and/or have a Sangaré replacement lined up, then I have absolutely no issue with moving him on now (even though I have liked what I have seen in recent games at the end of last season & the start of this). Failing that, I think I'd rather wait until January or next Summer.
From the outside, it feels an un-necessary risk - but we are not familiar with all the moving parts, and could not influence them even if we were familiar. We simply have to hope that the club know what they are doing with this one.