Drafting rules are useless. Every draft is different. You never know what position may get a run or how trades will change the board.
Drafting for need is how you fill holes. Do you take the 8th best CB or the best OC because the CB is rated a little higher but you need an OC.
What if you have Witten at TE. Do you take TEs in the 2nd round because they have the highest rating? And who's ratings are you using because yours may be inherently biased.
The other part of the equation that very rarely get's discussed is that the so-called "experts" are typically guys who have never even sniffed an actual scouting office or have been a significant part of any organization for that matter. The "experts" are guys who went to college to learn how to write for the newspaper and/or talk on the radio. Their expertise is typically the result of regurgitating the guys that came before them.
All the while, the actual football teams put together a draft board that ideally works its way down from who helps the team the most to who helps the team the least. More than likely they also put together similar boards for 31 other teams so they can attempt to predict how the draft will shake out and rather or not it will be necessary to trade up or down to get as many guys as their board likes as is possible.
Following the draft the mediots and talking heads will have the audacity to prejudge how each team made out and get paid handsomely for doing so because idiots like us just can't get enough of it, regardless of how much sense it actually makes or if they turn out to be right come season end. If they are right, they will write up or discuss on their medium of choice how they were right. If they were wrong, you will never here or read about an actual retraction.
Take, for instance, the nonsense that people have taken as the gospel that you should never draft a certain position in the first round. It has long been my contention that the Cowboys absolutely should draft Zeke at 4, if a small trade down doesn't materialize, because out of all the potential candidates to take, he has the potential to help the team as a whole more than anyone. One single defense player is not going to fix the defense, much less help the entire team like Zeke could.