Well, defense-wise, yes, dex holds roughly equally true for warriors as for assassins. And a point of dex means more when dex is high than when low, apparently. So the difference between 24 and 25 dex is supposed to be bigger than the difference between 20 and 21 dex. That said, once you've eaten a boneshatter, your 24 vs 25 comparison might well be more like a 16 v 17 comparison (i.e. relatively meaningless in terms of dodging).

The thing about warriors is that sometimes the best defense is a good offense. If you are a dwarf, for example, you might just be happy to soak up damage whilst dishing out a lot. At which point, dodge isn't so important. For an assassin though, I wouldn't say the various races have a particularly different damage output as a result of their strength, though others may wish to correct me on this. To some extent it depends on who you are fighting. e.g. If you are fighting a necro/ap/shaman say, you'll get some benefit from using staff + claws if you are a felar, which other races don't get by choosing a staff. (Staff can be a good choice against these guys because they don't know the weapon.)