I think that is true with the players are different order in the draft board. I looked at last years draft in my league and everyone in the top 6 got their first selection pick. The further down they went, they got there 2nd or 3rd choice. None of the teams in the first round were lower than than their 4th choice. The lowest choice was a team got there 23rd choice in the third round.
in this case you think he wasn't true right, because in this scenario is was usefull to get information about the strong players :) But with an active league, maybe with a bit higher draft investments, it could become not usefull to spend a lot as a top pick - i drafted on position 7 last season and get my 5th pick, the weakest pick in round one was the 10th choice.
But i would say especially when you draft late it is important to find a lot good players, because in the first position you usually get a good pcik and maybe just need 3 good players scouted.