I just looked it up because I didn't think that could possibly be right... and it isn't, sorry: MacKelvie, Ibanez, and Lark are all credited as pencilers on that series too. The Dodsons rarely manage anything longer than a five-issue stint on a series, and often little more than three issues in a row, and that's a trend that goes back years -- all the way back to their early days on Mantra.
And to answer GrandHarrier's question somewhat because it's related: it's said that top artists these days earn more money for covers and in private sales of their artwork to collectors, than through the page rates they receive from publishers for finished pages. As a result, they spend more time working on fewer pages and turning them into something a collector would buy, and less time worrying about churning out pages like in the old days when the private market wasn't there.