Like I said previously, the faster you make the game, the more it shifts your priorities from micro to macro tasks. Like, if I'm going to dick around with a grunt running in and tapping individual choppers once each to fuck up someone's wood, I can do that on EF without missing too much in my own base. On fastest, though, while I'm spending 15 seconds doing that, twice as much "time" has passed. I'd be better off focusing on expanding, upgrading, etc. This is super obvious with dragons - people actually use them on fastest, where as on EF they're too easy to pick off with death coil and a lusted dk or whatever, which makes them a waste of money. Also people use CTs more on fastest because opponents can't micro around the cannonballs as easily and because the cost isn't as high as resources come in more quickly. Oh, and the big reason being that if someone attacks your base on fastest, they can break through the wall more quickly and you have less time to respond with repairing etc. so the CT being an auto-attack helps a lot.