This argument used to come up in 40K quite a bit in regards to Eldar as they required coordination between units so there was a steeper learning curve. The thing is that the best players of other armies were also playing that way when talking about players utilizing the best tactics. Eldar almost forced you to think like a competitive tournament player from the get go so if you wanted to learn advanced strategies as quickly as possible when starting then they were a great choice for that as those same tactics applied to other armies. I imagine Wood Elves would provide that now in some ways, but their strategies are vastly different from every other army in the current edition that I feel you can't take your Wood Elf tactics and apply them to Greenskins or Chaos or pretty much any other army. When they came out a lot of their power was tied up with manipulating what was then considered some basic core rules that have changes drastically over a couple of editions. Even if using army books from then in the current edition they would face some of the same challenges they do now that weren't there in sixth.
The best players are the best players sometimes in spite of what army they are playing. Some of them their way of playing meshes really well with a particular army, but speaking in generalities the army does not make the player.