Duty Finder - It is not Gospel!
I don't know where this mentality came from, but fights were not designed around the duty finder.
I don't understand all the people complaining about fighting being harder with the groups compromised from Duty Finder.
The Duty Finder is a completely separate tool designed to give more casual players easier access to group content.
This does not mean that every fight in the game is designed for 2 tanks, 2 heals, and 4 dps. This is simply the setup that has the highest chance at victory with RANDOM people.
People need to look at the DF as more of an introduction to dungeons/raiding. If you want a better experience, this will ALWAYS come from a group formed on your own server.