I have a big that has 18 driving by now and I would not worry about this skill a lot - very easy to train. OD on the other hand is a painful skill to train for a big.
Größter Knecht aller Zeiten aka His Excellency aka President for Life aka Field Marshal Al Hadji aka Lord of All the Beasts of the Earth and Fishes of the Seas aka aka Conqueror of the Buzzerbeater Empire in Europe in General and Austria in Particular