The problem is not the number of jutsu someone could master. The main problem is how to use them and even if you can use them. Minato won't underestimate Madara. The time he will teleport behind him, he will cast directly a rasengan. Just see when Minato fought against Tobi. Tobi is someone who can pass through ghost mode in less than 1second, but because Minato FTG is too fast, the time he teleported behind Tobi thanks to a kunai, he didn't even had time to go in ghost mode. So when you say Madara's clone will have time to make shinra tensei when Minato will be behind him, not sure about that. If Minato really decide to kill him directly when he teleport behind Madara's clone, i'm not sure if Madara will have time to even see the FTG and cast shinra tensei just because even Tobi had no time to go through ghost mode. FTG is so quick. Even after that, he hadn't even time to see FTG when Minato came the second time to nullify his control of Kyubi.
The databook even says that FTG is untracable, and that makes it difficult to notice quickly.
What you also forget is "information". Madara in the contrary of Tobi is not suppose to know that were Minatos kunais are, or where his markings are, Minato could simply teleport there and kill him. So he won't pay attention of that, and Minato could take advantage of this. Susanoo has a weakness which is attacking from underground. So if for example during the fight, Madara stays under his markings or kunais, Minato could easily finish with him by teleporting quickly there and kill him.
I acknowlege Madara is strong, too strong for Minato, but saying a clone from him could kill Minato(the fastest man of the world, the one who has the best reflexes ever) that easily is greatly underestimating him.
What could even work in favor of Minato is that when he is smart like hell, Madara is the one who underestimate his opponents, and it could be dangerous against Minato.