So I want to make a new subrace of goliaths who maintain the traditions of an ancient and erudite civilization. In keeping with the pattern for subraces, they keep the same primary score bonus (+2 Str) but have a different secondary bonus. The thing is, I kind of want them to excel as both wizards and bards. Looking at the half-elf, a bonus array of +2 Str, +1 Int, +1 Cha is apparently sometimes justifiable, and looking at the mountain dwarf, you can sometimes have extra bonuses even when other subraces of your race don't. Do we have any idea about the rhyme or reason behind these divergences from the normal +2/+1 pattern? I want to do do this, but I'm worried about power creep if I make a habit of it.