The way I'm reading the article, you used "Mutator" correctly, but not "Swap." The latter term refers to a piece's ability to trade places with another friendluy piece, such as with udQ. I don't think the article identifies replacing a piece with a different piece from the start.
The way I'm reading the article, you used "Mutator" correctly, but not "Swap." The latter term refers to a piece's ability to trade places with another friendluy piece, such as with udQ. I don't think the article identifies replacing a piece with a different piece from the start.