I think you are overrating Munir
How so? To suggest that Sandro is better because of a solid performance against the worst team in La Liga is where the real overrating is taking place. Munir has better touch, clinicality, defensive effort, linkup play, 1v1 skills, etc than Sandro, but because Sandro has 2 goals now and Munir has 1 Sandro is suddenly better?
Think of it this way. Munir is a first team starter. Sandro is a super sub. It is this way for a reason.