I think they should each be allowed to trade whatever vehicle or combination they choose. What matters is whether they can produce results, with their own method.
I didn't include Larry Williams because I don't think he posts on here.
According to Sabena he sent him an email telling him that he is prepared to take Williams up on his boast that he (Williams) will trade against anyone.
Apparently no response came forth.
Perhaps Williams eyesight has deteriated to the extent that he isn't reading his emails nowadays.