I believe the design was done because at the time the FAA imposed some tough take-off weather restrictions on twins
Certainly wasn't aware of that sort of consideration (and I've never been too involved with US operating rules as opposed to Design Standards). Can't really say that I see any great logic but, then again, I've been way off the mark in the past so no reason why I can't be again.
For interest, the current Oz requirements from the AIP are
here.
I'm only in my final year of secondary school
Go for it, mate. Give you, say, another thirty years and your name might have become a household word.
Now, are you looking at RMIT ? or something like Sydney or NSW ?
A budding Henry Millicer in our midst.