Positionally Mahrez is a bit of a luxury as it stands, but if Bernardo & Sterling are earmarked for being sometimes used in other roles (Sterling seemed to be the subject of several central experiments late season) then it becomes more logical. Mahrez feeding Sterling's pace as he does Vardy for example.
Re the left side: some of Jesus' best performances prior to signing for City, imo, were when he played on that side, including some great defensive effort, & although he's shown nothing yet for City, when moved there, it doesn't mean he won't do in the future, if Pep decides to use that as an option.
The upside of Mahrez would be, imo, that he'd be coming here as someone who wants to prove himself, not as someone who thinks he's the star man, & that he is a tricky fucker, who may open up spaces v bus parkers.