With all due respect that's pure speculation. Filler, Chang and SVB make enough money playing the don't have to teach. Nobody knows how good they would be as a teacher but I suspect a decent player could learn a lot.
No, it isn't speculation.
One's playing Fargo is a measure of playing performance, not a measure of what kind of player one could possibly become. A hypothetical Fargo for teaching would be a measure of teaching performance, not a measure of what kind of teacher one could possibly become.
So, yes, Filler, Chang and SVB would have low teaching Fargos relative to the stars of the pool instruction profession, because Fargo is, and always has been, based on performance, not on potential.