In a way the guide could be considered accurate on the way THEY score it. The guide only includes 6 categories. Offense, Defense,Projectile,Final Smash,Throwing, and Speed. By only counting those 6 categories the guide would be correct. But in reality their is a lot more that creates an actual tier list. They are missing some basic key factors that would actually make this a more reliable semi-tier list, such as KO-ability (Offense is only based on how much damage a move does, not the knockback) , recovery, range,etc. And they also included some categories that make no complete sense...I mean come on Final Smashes shouldn't even be included for the fact is most competitive play has all items off. And why the hell is projectiles a category....not everyone in this game has an actual useful projectile so it would move them down on the list compared to people that don't have a projectile at all.
So in the end on the categories that these people set up the list is possibly flawless, but if you count other things like range, knockback,recovery, weight, size, spikes, advantages, at's, etc. these people have no idea what in hell they are talking about.