some really constructive and insightful replies you've prompted, especially the first three or four. doesn't sound to me like you're questioning the manager. or writing off the player. but sometimes people like to put words in other people's mouths.
to be fair aguero's actually a pretty versatile forward. his link-up play, pressing and recovery of possession all improved a lot in the 100 pts season when he managed to adapt his game to suit guardiola's tactics, something i think he's capable of doing again. i don't think we'll have to completely overhaul the system to accommodate him, and i think his all-round game is strong enough that he'll be an improvement on jesus in the role that jesus currently offers.
the midfield will probably be a bit less fluid, and gundogan and foden will probably play a bit more conservatively and chip in with fewer goals. on the other hand, we'll benefit from aguero's goal return and the different sort of threat he offers (obviously assuming he's fit and in form), as well as his wider contributions as a hardworking team player and complete centre forward. so my ill-informed guess would be that we'll be able to fit him into this year's system a bit more seamlessly than you're suggesting.
then again, we might have to change everything to accommodate him. or change nothing, and he barely plays for the rest of the season. ever since stones turned things round and made himself undroppable, i've stopped making grand predictions about this side with any great confidence.