Jiraiya already answered this, there hasn't been a genius like Minato since Minato and Jiraiya knows Itachi, Shikaku, im not sure if he knew about Shikamaru but his dad is smarter than him so it doesn't really matter. If Jiraiya was wrong then Tsunade would had said there's Shikaku and Shikamaru like when Jiraiya told her only she can be Hokage and she said there's Kakashi and Naruto when his time comes. Jiraiya then sai fair enough to Kakashi but said Naruto is not there yet. Why would Tsunade not have done this with Minato being genius that no one have been able to match or surpass? Tsunade does know about Minato, Shikaku and Shikamaru so that proves who more of a genius.
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Also Shikamaru strategies are more about how he can use other people's strength to help him win while Minato is able to see jutsus strengths and weakness to make a strategy on how to beat his opponent. He also was said (by Jiraiya) to not make a wasted move which means all of his moves have a reason. He was able to rebuild the ttb into his own A rank jutsu just by seeing the tbb (most likely fighting Bee and A). Minato Shown he knows about jutsus he haven't even seen (Tobirama's sensing using his finger on the ground and his S/T jutsus even tho he wasn't alive when Tobirama was). He also shown wisdom by being able to think about the big picture while under pressure (Minato choose to die so he can seal half of Kurama's power in Naruto so : 1. the balance of power among villages remains. 2. didn't want Kurama to revive later on without a host so it doesn''t cause more damage. 3. He believed Tobi would be the bringer of great disaster and only someone with special powers could defeat him once and for all).
