This sort of thing is very common among video games.
Part of it, especially in CRPG's, is trying to make a weapon actually visible at the distance and scale that a player will be looking at them. So their actual models are normally far bulkier than an actual real weapon would be.
This is of course, on top of silly "Weapons just float next to you while sheathed" things which further detract from any sense of realism.
It would be very nice (As someone who's a medieval weapon enthusiast) if we got more accurate models for weapons and actual systems for carrying them (Sheathes for blades, loops to hang axes/maces from, hooks to support bows/crossbows) - With of course, things positioned so that all equipped weapons are always visible.
Such things would go a long way in terms of aesthetics and overall design.
