The must show 3 examples logic is an awful remnant from ad agencies where the thought was that it's always best to give clients 3 options to choose from because:
- it makes it look like you did a lot of work
- it gives the client the perception that it's their idea by being a part of the choosing process
- it offers up a way to determine the direction a client wants to go in when they aren't entirely clear up front.
Of those bullet points, only the 3rd one is a true design process benefit. The other 2 are just sales bullshit.
Unfortunately, a lot of people still subscribe to that bullshit. And it's not usually good for design.
Sometimes it is, and the alternatives come naturally and hey, that's great! Go with it.
But when it doesn't come naturally--often because it's fairly clear that based on the requirements there really is only one best option, then you just gotta get the barn shovel out and start flinging. At that point, just randomly create two variations of what you already have for the sake of saying you did 3. Make the sales folks happy. Keep your job for another week. :)