The importance of a consistent code structure is rather important for the overall health of any application. The order in which declarations and methods are placed has a direct impact on maintainability as a project grows in size and scales beyond a few thousand lines of code.
Each of us has experienced the time-wasting frustration of not being able to quickly locate methods and properties. Scrolling and searching our way through classes with thousands of lines of code is not a particularly great use of our time. Having a consistent class structure will keep source code neat and tidy and aid in shortening the transit time we spend jumping between class methods.
One particular strategy that I find helpful for organizing