Here is the thing about most of these build sites. They want you to have end game gear that requires running content that frequently needs the gear they are telling you to wear. I always chuckle at Maelstrom Arena Builds that tell you the first thing you need is a staff from the Maelstrom Arena. Really? The content I want to run needs gear from the content I want to run so I have to run the content to get the gear I need to run the content?
Here is how you use these build sites. Get ideas from them and use the ideas, but don't copy the builds. Like Deltia for instance, he is great at explaining why some skills work better with other skills and why some set bonuses can make some skills or rotations really effective. Take those ideas and fold them into how you play the game and the gear you have, and more importantly the gear you can get. You will find things will work so much better for you.