At least in my ideal poster-space this hierarchy would be included. Considering that knowing about biases can hurt people having a general theme of how to resolve arguments better rather than "here are some fallacies, avoid them/point them out" can't hurt.
You could make a top level distinction between problems with arguments (or how they are presented) and problems with thinking (or decision making), though there would be overlap. But I think, for a single poster, it might be overly ambitious to try to include both logical fallacies and cognitive biases.
And confusing - if someone makes use of a fallacy in an argument, is the bias in the person who is persuaded by the argument, in the person presenting the argument, or both?
Following http://lesswrong.com/lw/bwo/logical_fallacy_poster/ some people complained about
Yet this poster has ONE key difference with the ideal poster, it exists.
If it sparks criticisms that lead to a new, LessWrong compatible poster, then it is well worth the critics.
The obvious next step then is to make a poster that would allow to take into account such well founded suggestion and synthesize the LessWrong lessons visually.
In your opinion then what would be a good structure, e.g. a hierarchy of fallacies, and a design theme?