As TDawg himself said, this isn't really about finding people that fit a certain type in Madden as much as it is about you finding the players that fit the way you play. For example, I HATE dropped passes in Madden so I can make sure that I have a high weighting on both catching and speed. In the archetypes, that's not a combination that Madden will use (unless I'm remembering one of them wrong). They're both factored in but some put more weight on one than the other. This tool lets me weight them both as my top factors, if I want. Using the percentages, I can say that I want great hands (set at 25% or so) and I'm willing to sacrifice spectacular catches (2%) to get that.
Just remember, this is a tool to help you evaluate your roster and players. You can get a guy with pretty high ratings here that Madden might have rated pretty low. If you use him the way you indicate in the tool, he can still be pretty darn good though.
Now, you can use certain archetypes as a foundation, if you want. Just look at the description in schemes and weight the elements that it mentions higher.
If you can't tell, I already LOVE the tool. Not that I'm surprised but this is awesome.