It was a recommendation due to the fact that many users had had problems with Tomahawk. Now, the MyFaces team claims they have done work to solve this problem, and I had meant to remove that line from the docs.
We are working very hard with the icefaces and ajax4jsf teams to iron out issues encountered by Seam users. We will do the same for Trinidad when it is released. However, I cannot commit to spending any time on the Tomahak stuff, because it simply isn't as interesting to me as the other three libraries.