^ It is exactly as he said. But if you want like most people you could slower pok'emon like skarmory,jellicent,regice,tyranitar etc. Because even though they are slow they pack a big punch. Really I could probably rant about this all say but I won't. Speed is good but it's not everything,enough said.Speed is important because it's the only stat that, when calculated into the game, is completely black and white (pun intended). Either you attack first or you don't. Other stats are different since they affect damage on a percentage basis, and while one speed point can be the difference between life and death, one point in one of the other stats probably will not. Having tons of power means next to nothing if your opponent hits and kills you first, which is why Rampardos is in NU right now; it hits hard, but it has neither the speed to beat many offensive threats or the bulk to take hits from the faster ones.
Not to mention that the POTW doesn't make that much of a deal about speed. Many Pokemon function perfectly fine even without much speed at all, such as Ferrothorn and Reuniclus. While speed on a defensive Pokemon is nice at times, it's usually going to be a priority on offensive Pokemon. If an offensive Pokemon has plenty of bulk, then it can usually function properly even without speed because it doesn't mind taking a hit all that much. Conkeldurr is actually a great example of this. However, if that Pokemon is fairly frail, then it needs to have a high speed stat to make sure it can kill off the opposition before they kill it. This is why Pokemon like Darmanitan are in lower tiers; their speed stats are just low enough to lose to a vast number of offensive Pokemon in the upper tiers, and they don't have great bulk to compensate.