At the time I created the guide, 1 damage did equal 1 skill damage. Most equations were pretty much extremely linear. I think changing their formulas around was very much needed though because most characters were already OP due to skill damage in any campaign map prior to the latest patch (I haven't had a chance to play it though). I'll be respecing and playing around with stats and skills to update my guide...or if someone would like to do it instead that'd be great =p