MCK, people say that, but those people are wrong

Seriously, it's completely incorrect. Most of the cake we make here is hi-ratio - meaning the weight of the sugar is equal to or greater then the weight of the flour. Mess with that ratio and your cake will fail.
The difference in finely tuned recipes is leavening. My base recipe is the same but I adjust the leavening based on weather I'm making cupcakes, an 8" cake or a 16" cake. It has to do with how much gas is required to expand in the batter to set the structure while working with the surface tension of your batter being tight or loose based on the size of the pan you are using.
Most published recipes have leavening for a typical 8 or 9" cake. But a lot of those recipes won't work if you try and make them into cupcakes - they have to much baking powder or soda so they deflate, pull from the papers, or stay pancake flat.