A smaller tip does not mean you will get more English on the ball as compared to a bigger one. The only thing a smaller tip does is allow you to hit more precisely the English you want to apply. It doesn't matter what size tip you have, or what tip curve you use, if you hit the exact same spot on a cue ball with all variants of tips, you will get the same action out of the cue ball. Now a dime curve tip allows you to reach farther out from center cue ball than a nickel, giving you more English. But as far as tip size and English, there's no correlation.
Edit: Note that different tips have more effect on English than the actual shape or size.