User blog comment:The ASL Pirates/Traveling Back/@comment-10543621-20150720063525/@comment-26803131-20150721231221

I think that there are always 4 emperors. Reason being couldn't two crews have risen in Whitebeard's fall. And after it was said that either Blackbeard or the remanents of the Whitebeard Pirates would likely take the 4th spot. Otherwise both crews could have attained the title. But those two may have been mentioned due to their knowledge of Whitebeard's territory.

Another reason the I believe that there are only 4 emperors is due to the fact that there are max 7 warlords. If the warlords are there to keep balance and there were less emperors then wouldn't there be less warlords as well?