What exactly are you trying to do?
There might be an easier way to go about this if we knew what you were trying to do in the family, but an if statement requires you to have an "else" condition in it: If (this), Then (This), Else (This), and I'm not really seeing how you could set these parameters up using if statements.
I know you can write more than one if statement into a single formula but then the if statements will become conditional on each other.
An example that might be similar is I had to create a large tank family used for holding alloys and stuff. Inside the tank was a divider that had spacers in it and if the width adjusted, the spacer count had to change.
What I did was create the spacer as a nested family (easier to control,) arrayed it and then wrote an equation to control the spacer count by telling Revit how many spaces it needed.
The same could be done for a window. If I want the window to have three lights then it needs 2 mullions.
So you would have to also write an equation to say that Mullion Count = Light Count -1.
Then apply the mullion count parameter to the Array.
Sorry I can't give you the exact formulas right now, but if you would like them just send me an email and I can give you the exact one I wrote when I get to the office. I'll send you a screen shot of the Family Types so you can just see all I wrote for it.
On a related note, watch out when controlling an array count with a formula as they have a tendency to keep adding members outside of your family. You can also control in the equation.
Sorry for all the gibberish, I hope you are able to make some sense out of this mess.