He is just/but one of many good students of our class.

[Nonverbis]

Could you tell me whether I'm right that 'just one' is infrormal, 'but one' is formal.


Examples:
He is just one of many good students of our class.
He is but one of many good students of our class.

 

[Tarheel]

I don't consider either of them formal. I do think the first is more likely. (I could be wrong.) I would also use "in" and not "of" there. (Others may disagree.)