In the end, I think the question of "realism" isn't the question we should be asking.
When considering a rules-system, the question is often more suitably, "Does this system allow my friends and I to tell the story we want to tell with an acceptably low impediment to suspention of disbelief?"
Let's look at the repercussions of this splitting of Dex into Dexterity and Agility...
Well, we have a new stat. Now, we must go over each skill and feat that depended on Dex and revise them. We need new spells and magic items for buffing the new stat (hm, there are usually only so many magic item slots on a person, does this cause us issues?). We need to realize that adding a stat means that (all else being equal) the average stat will drop (you're now splitting your 1 point every four levels into 7 stats, rather than 6), which can become a problem when we start considering how these stats feed into feat trees. We need to all the Dex-heavy Prestige Classes...
That's a lot of work, for a small upgrade in versimilitude. I'm not at all convinced that it actually improves the story. Unless having one stat is really getting on your nerves, I doubt it's worth the hassle. I think most folks would prefer to not have such a change.
Now, think of this: Wolfen Priest, you may be in favor of such a change - you may really like the additional realism. But would the rest of your gaming group prefer it? You'd be happy, but that happiness may be partially paid for by a number of minor annoyances to other people. Is that worth it?
When considering a rules-system, the question is often more suitably, "Does this system allow my friends and I to tell the story we want to tell with an acceptably low impediment to suspention of disbelief?"
Let's look at the repercussions of this splitting of Dex into Dexterity and Agility...
Well, we have a new stat. Now, we must go over each skill and feat that depended on Dex and revise them. We need new spells and magic items for buffing the new stat (hm, there are usually only so many magic item slots on a person, does this cause us issues?). We need to realize that adding a stat means that (all else being equal) the average stat will drop (you're now splitting your 1 point every four levels into 7 stats, rather than 6), which can become a problem when we start considering how these stats feed into feat trees. We need to all the Dex-heavy Prestige Classes...
That's a lot of work, for a small upgrade in versimilitude. I'm not at all convinced that it actually improves the story. Unless having one stat is really getting on your nerves, I doubt it's worth the hassle. I think most folks would prefer to not have such a change.
Now, think of this: Wolfen Priest, you may be in favor of such a change - you may really like the additional realism. But would the rest of your gaming group prefer it? You'd be happy, but that happiness may be partially paid for by a number of minor annoyances to other people. Is that worth it?