Bob, I think perhaps it's not too surprising that Gerard used more incantations than the people you mentioned. Nicholas and Petofi had other interests: Nicholas was busy developing diabolical plans for his Master, while Petofi had his love of music (and possibly his love of Aristede, for a while) to keep him occupied. And Angelique, being a woman, used magic to get what she wanted (or anyway, to try to get what she wanted) without being terribly concerned about the means. But the whole revenge-upon-the-Collins thing really wouldn't have been much of a hobby, so there Gerard was, a man with too much time on his hands. Naturally he played with his version of power tools.
I suspect this explanation may be open to refutation, but I like it anyway.