One of us is misinterpreting that sentence, let's see who that is,
They are speaking in past tense because he is dead dude..
If someone says orochimaru has the talent to become the strongest shinobi-
It means while he isn't the strongest shinobi , but has the aptitude to become it
jiraya says Minato had the talent to become extremely strong, then tsunade says but he died quickly...
it means he didn't have time to use that talent
You're saying that Minato didn't become a top rated ninja, the Minato who has sealing techniques that can seal Kurama, who wiped out armies in the blink of an eye, who became Hokage, who defeated Tobi, A(the next in line for Raikage) and Bee, the same Minato ninja were told to run from under any circumstances, the ninja who won the Third Great Shinobi World War for Konoha. That's who you're saying Jiraiya is calling 'not yet a top rated ninja' while my interpretation of the sentence is that he is a top rated ninja. Who do you think is wrong here?