Why not make all the heads available to all the races. I mean, they are all scanned from real-life human heads. If humans can have such variety, why not elves?
These are scanned faces that were later remodeled by graphic designers (you can find it in their character creation diary). There is variety (in Forgotten Realms lore), but within their racial characteristics. The same as with Chinese people who are different from each other but still share some common characteristics within their ethnic group.