You might need to look around more. The wikipedia article shows 'c' on the middle finger, like I was taught. I can't imagine doing it with the first finger, but I suppose it just depends on how you were taught.

Looking around, I can't even FIND a "c on first finger" fingering.

- https://en.wikipedia.org/wiki/Touch_typing#/media/File:Finge...

- http://www.typingme.com/touch-typing/typing-lesson-9.php

- https://agilefingers.com/articles/touch-typing-finger-placem...

- https://www.computerhope.com/issues/ch001346.htm

- https://www.ratatype.com/learn/

and on and on.