@Jeff Skyrunner: The sheets will load in the order you include them and finaly the including sheet will be loaded last.
@Ashley: Actually it has an impact if you're using several "On start of layout" events, spread in the included sheets.
You have to make sure you're logical in what you make happen first, and/or about the values you might set to certain variables.Example
. According to where/when you're setting the value and/or adding to it, you may have some unexpected result to someone not aware the included sheet is loaded first.