I stand by my contention that is absolutely harder to paint in oils than to sculpt, draw or even use pastels. Others before me have said so too. For every skilled drawer one may find one skilled painter. This is normal and typical.
Once an artist can handle color and oils he will seldom retreat to drawing. This is historically so. Drawing becomes a step to the finished oil. Cartoons are torn up and tossed away. The colorist becomes disdainful of his own b/w work. Hundreds of artists have done this; WB, Sargent, Rubens, Michelangelo, even Rockwell. Paintings sell, drawings don't. For the painter these preliminary works are just that. They literally pale in comparison to the paintings. I'm biased, but I'm not the first painter to be so.