Well, if you want a bunch of baseless conjecture and house rules, here you go:
Orc: +2 STR, +2 CHA, -2 INT
Goblin: +2 DEX, +2 INT, -2 STR
Hobgoblin: +2 DEX, +2 WIS, -2 CHA
Kobold: +2 DEX, +2 CHA, +2 INT, -2 STR, -2 CON.
They're already more or less kitted out with racial abilities. Figure...