We've been with the series for a long time now. There are a lot of topics that we all take for granted because some important characters say it in the series. In the beginning of the series was stated that there is this balance in the world between 3 superpowers: The Marines, the warlords and the yonkou. It is stated that they are all equal in strength. I'm not trying to underate any character or major group as a whole but right now i'm having some trouble believing that the group of warlords are equal in strength as the emperors.... i mean i believe that we haven't seen all the marines strength so i don't have trouble believing that they equal the emperors in strength but the warlords we've seen some of them... heck we've even seen some of them get defeated, while it took the two groups (warlords and marines) to take down one yonkou. True it was said that Whitebeard was the strongest, but the others are supposed to be monsters as well.
It's true enough that we've not seen the supposedly stronger warlords go all out.
So what do you guys think about this are the warlords as a whole equal to the yonkou or the author really meant that marines + warlords = yonkou in overall strength (even thought i'm almost sure Oda didn't mean this).