You said Orochimaru would only be able to counter the Kyuubi that he STOLE from Tobirama. FTG is Tobirama's jutsu, Minato technically STOLE that too.
He didn't "Steal" it in any sense of the word. Saying that would be like saying all ninjas stole Tobiramas jutsu because he created the shadow clone jutsu.
The difference between Orochimaru and Minato, is that Minato was
handed down the Jutsu that he was ABLE to learn. Orochimaru
STOLE the Jutsu from the Hidden leaf and was outcasted for it. The reanimation jutsu was, and is, a forbidden Jutsu, hence why it was hidden away in the Leaf Village. That is why he
STOLE it and was NOT handed down the jutsu by Tobirama.
Orochimaru isn't top in tactics? Seriosly?
Apart from all he acheved in terms of jutsu, knowledge etc., he managed to run several hideouts with hundreds of prisoners while being number 1 in the bingo book
Overall, Orochimaru is easily top1.
And what has Minato actually done so far in terms of being the smartest/most intelligent that people place him in top1/2? No hating, just asking.
I don't know, Upgrading Tobiramas original design on the FTG and USING IT TO DIVERT A TTB is a pretty decent feat. Hell I could go on a limb here and say that if it were not for Minato, Orochimaru could have been killed that day.
Another thing, before you try to say that "oh Orochimaru would have just revived himself..." You have to remember that when Kurama attacked the hidden leaf, Orochimaru didn't have much (or any) research completed. Not with the Reanimation, or any other hidden/forbidden jutsu. So by extension, Minato saved Orochimarus life XD