The sample size itself is fine, but the amount of time isn't. People do play differently when progging vs speed kills, and WHM is usually favored for prog while AST is favored for speed. This early in the patch, this could cause WHM to have lower dps (especially for new fights) because of playing it safe, while the AST logs are probably for groups that are already thinking about numbers and efficiency. As time goes by, the WHM will be playing less safe and pushing out more dps.

It's worth watching, but I wouldn't be too worried about numbers from the first week of a patch.