well, but sometimes the best players are bad teachers, have no interest in teaching or cant be bothered to help anyone out if there is no gain for them.

as you stated, making the "best" ingame players something like TA's to help out beginners aswell as experienced players won't work out.
without naming any of them, but the ones which come to my mind clearly would be terrible teachers, won't work without a gain for themself and mostly play this game to duel/bet and earn money with it. why should they bother with teaching other players which potentially could break their niche and lower their income?

otherwise i have no clue what sort of players you mean, to gather for the job you specified.