Sane-Jesus-Sterling isn't so far away from MSN, with the key difference being Suarez is a natural centre forward.
Pep doesn't like strikers, they don't work so well with his system. At Barca, arguably the best Barcelona team in history, he played with zero strikers and stuck Messi as a fake number 9 which seems to be what he's aiming for with Jesus.
At Bayern, he accommodated Lewadowski and I have no doubt he can and would do the same for Aguero. The thing is though, Kun hasn't been playing well this season and his current run of form particularly makes him a less reliable option. Further, it isn't clear that Sergio has adapted to Pep's style (he runs less, gives away possession frequently etc) and it's hard to justify including him over another of our front three who have genuinely clicked.
It's obvious Aguero will come around again, he's the best striker in the league by a measure. I have no doubt the club, and Pep, consider him irreplaceable and will make every effort to keep him in the summer. The only questions are if he himself wants to remain, is willing to try harder to fit in Guardiola's system and can accept results are paramount therefore automatic inclusion isn't ensured.