What if the Ferengi in TNG maintained the idea of being the main antagonists? No bumbling humorous vibes out of them, but instead, they are cutthroat ruthless Capitalists and are hostile to the Federation as a whole. This means that later on in DS9, they are not the humorous comedic relief Aliens, but rather an intimidating hostile race. Assuming the Ferengi are written completely different from the get-go, no "Yankee Traders" sort of thing.