Racial restrictions don't really solve the dilemma, they just hide it a little.
I'm a little uncomfortable with racial-linked skills ... I'd prefer that racial specializations emerged more naturally (from simply being the better combination of attributes, rather than being forced upon players, even though it might not always line up with the originally-imagined fiction and the dynamic may change from patch-to-patch as balance tweaks and content changes alter the best character builds).
I'm also worried that the concept of a skill is continuing to gain complexity - we already have skills with prerequisites: remove traps (requires detect hidden 50), masonry (carpentry 100 to learn), glassblowing (alchemy 100 to learn), spellweaving (quest). I would prefer the concept of a skill be simplified (merge lockpicking and remove traps abilities into a single skill), reclassify alchemy/masonry into recipes instead of a "skill", etc. Adding racial limitations feels like a step in the wrong direction ... but that's a whole separate debate.
Currently, I feel that swordsmanship, fencing and macing don't have enough to distinguish them ... it's a different selection of weapons, but really it comes down to what properties/speeds/specials you manage to accumulate on the weapons - and there's more variation within each group than between the groups.
So what distinguishes archery and throwing? As far as I can tell, it's a similar situation to the swords/fencing/macing situation except throwing gets to dispense with archery's distinguishing limitation (requiring ammunition). Making the skills race-restricted is almost like just saying "gargoyles don't require ammunition". Unless there's some difference to how monsters/players/puzzles react to being hit by a thrown weapon vs an archery weapon, I'm concerned it won't be distinct enough.