Sorry I was mistaken it was "lack on"
"Your argument is lacking on all scientific merit."
This is a sentence from the big bang theory season 2 episode 11
"Your argument is lacking [,] on scientific grounds."
This is a good sentence. But it doesn't use the collocation "lack on" (which probably doesn't exist). It simply follows "Your argument is lacking" with a prepositional phrase giving the reason - "on scientific grounds".
This was possibly the intention of the original, but with 'merit', I'd use "lacking in".