I'd suggest that Half-giant gets their own racial category: Half Giant
The reason is that [1] they're not full giants and should not be RP'd to have full size, and [2] there's a large number of bonuses specifically targeted at Giants, most notably all dwarves and gnomes get +4 AC (which is a huge advantage compared to other minor racial bonuses).
This is in the context of half-giant already getting -1 AB/AC, -4 MS / Hide / Spot / Listen from being Large.