See I disagree with some of this. Dale was as strong as an ox but I think the thing that set Dale apart from other muscle player (Kevin Willis come to mind) was the fact that for a big man he was cat like quick when he was younger.
In fact I think in terms of lateral movement he may have been as fast as any big man that I have ever seen, including Garnett.
You may be remembering Dale in the 04 season when he was in his mid 30's and much slower.
When you watch Winning time next weekend, pay attention to the one shot that they say put an end to Ewings career as an elite player. They talk about Pat getting confused and thinking that he was going to draw contact from the defender and get fouled. He didn't, he missed the shot due to the shot being contested enough and he didn't get the rebound because the defender not only sidetepped him for the layup but was fast enough to beat everyone else to the ball to secure the rebound and thus the game.
That defender was Dale btw. That playe was a combination of skill (not fouling) and speed (getting from one spot to another before anyone else could).