In the first 2.5 seasons he was also a one-man team in terms of scoring, whereas Agüero has constantly had others around him at City who have shared the goals out. It wasn't until that final season he had support from Sturridge, Slippy G also chipped in with more than usual.
It would be interesting to see Suarez in Klopp's Liverpool with all their attacking football, he'd probably score 30, but Agüero is also a fantastic sniper and one player I wish we had signed.