I agree on the first and second part. I do not think that every player in OG plays very well though. Moons aggressiveness is exactly why I think he is one of the worst offlaners in a top-tier team, because he generally dies once or twice on the offlane every single game, occasionally getting something out of it when the opponent makes the mistake to overcommit. None of that is intentional though, he is way too inconsistent to have any method to it. The only reason he manages to stay relevant after usually losing his lard so hard that he cannot even lane anymore is thanks to Iron Talon. Fuck that item in the ass, seriously. His heropool is basically limited to heroes that have the option to utilize Iron Talon (Slardar, Void, Beastmaster) or are generally great at jungling once they hit at least level 2/3 (Bat, DS, Tide, again Beastmaster). And he almost always has to because his laning is one of the weakest out of any of the offlaners out there. If it weren't for IT, you could just outdraft OG based off of that. He is way too slow to adapt to new heroes, thankfully this patch around he doesn't have to.
Fly on the other hand usually gets easy to play defensive supports, which doesn't really matter because cr1t is just so beastly on whatever roaming support you give him. Compare him to most other pos 5s and he falls short by quite a large margin though when it comes to gameplay itself. He does the drafting and OG always manages to get a very knowledgeable coach too, so he certainly influences the outcome of the game in other ways.
Notail is just the silent type in terms of gameplay, never even trying to outplay his opponents which makes him a better player than say rtz or envy who usually try to do stuff by themselves when they feel like they're behind, oftentimes feeding their gold-advantage away. If miracle gets outplayed or pressured too much for even cr1t to save him, even with great farm notail rarely really manages to turn a game around. The game is either going great already and notail had very little to do with it initially, or the game is going badly and you cannot rely on notail to turn things around no matter how farmed he is. What he did well this tournament and has been getting better at already in the past couple of months, is joining his already winning team and securing a victory, not throwing away the advantage his teammates usually build by themselves. Not a bad player by any means, but certainly not a t1 carry either.
I think there's a reason OG never gotten close to winning another tournament or qualifier after the frankfurt major(though they usually didnt join a qualifier if they did not receive a direct invite), and while they did win a couple of LANs in the past months those were very low quality when it came to their opponents. They did finish 3rd at epicenter, but placed behind the only two teams that could be described as t1 teams at that event. I am certainly surprised to see them succeed in the WB, but I always feel like their games aren't quite as exciting gameplay wise as other games, for example the liquid/lgd or newbee/lgd matches. It's a joy to watch miracle and especially cr1t though.