Gambit is usually considered a work of fiction. It might draw inspiration from various sources, but it doesn't represent real events or people in a direct way.
Some characters might develop their gambit powers through intense training. Just like in the original Naruto series where characters train hard to master their ninjutsu, in fanfiction, they could push their limits in special training regimens to unlock new aspects of their gambit powers.
Gambit's height in the comics is kind of flexible. Generally, he's portrayed as being around six feet tall. But different illustrators and storylines might give a slightly different impression of his height.