Indeed there are many ways the snake could have been designed - I guess Montblanc wanted to align with the design of the serpent on the pen clip of the historic “Rouge et Noir” fountain pen to make it their 110th anniversary watch.
The LE non anniversary edition is what I like too. If only I have the spare cash ! It's a grail out of my league to be honest 
But I really love that bi-cylindrique Tourby in action !
Cheers
Robin