User blog comment:Blackendedsoul/Roger's Equal/@comment-3119203-20110217032434/@comment-3425840-20110219031629

Firstly, Kong did nor fight the war because he is no longer a part of the navy, he is now the world government commander in chief. The war was between the Navy allying with the Schichibukai versus Whitebeard pirates and there allies. Therefore Kong had no reason to fight in it.

When Blackbeard killed Whitebeard, he did not have the power of the tremor tremor fruit and after two years he surely have improved.

As for Shiki, Luffy being able to defeat him (though luckily) even before the time skip made me doubt his power.

Shanks: Yes he had time to improve, but he also had lost an arm and no matter what Whitebeard said, we can easily deduce from Mihawk's statements that it did weaken him to some extent.

Kaido and big Ma: there are possibilities, however even though they are Yonkous, reputation wise Dragon seems much more sinister than them. As we are in the dark about the powers of all three of them, it is likely that we have to choose from reputation alone which gives Dragon an edge.

Gurousei: well all of them has scars which seemingly are from battles in the past and as for all talking and not fighting I can only say that they did not need to fight yet.