cEDH decks make up level 9 and 10, which I think is a fair assessment. Judging these decks based on their turn count isn't always reliable. Proactive combo decks (
Flash Hulk,
Food Chain, storm decks) will try to race as fast as possible, and will only interact with other decks for the sake of protecting their
game plan. Disruptive decks don't race to win as quickly as possible, but instead use removal, counterspells, and stax effects to mess up their opponents, before setting up their own win. Adaptive decks are the sort-of grey area in between. They try to switch between both tactics.
As you can probably guess, each of these types of decks win at different speeds, but they are all viable tactics for competitive commander.
As a general rule, most decks will try to
threaten a win by turn 4, with many proactive decks trying to do it sooner. What's more important is the speed that these decks set themselves up. Turns 1 and 2 are your set up turns to play mana ramp, card advantage, and light stax effects. Turn 3 is when people make their big move (usually casting their commander). Turn 4 is when people try to win, or start taking steps to stop others from winning.
If you have a deck that does any of what's described, it could very well be a cEDH deck.
The problem is with rankings 8 to 1. It's pretty common (at least with me) that I have people that overrate their
Atraxa, Praetors' Voice deck. They think it's a 10, because they haven't seen what a 10 deck can actually do. After someone played against my Krenko deck, they said "Yo, Krenko is one of the top 10 commanders of all time." To which I said "He's not even in the top 50".
This is probably also why I rate my decks lower than everyone else. Even though Krenko and
The Scarab God are both well built, there is a massive power gap between the two decks.