how is Kent different from Oswald?

Both these guys are servants and loyal in their own ways. Kent is really the personification of loyalty. Even after Lear banishes him Kent sneaks back in disguise so he can keep serving Lear. Oswald serves Goneril but is slimier than Kent. While Kent represents a wholesome loyalty, Oswald isn't afraid to cheat and lie for Goneril. Oswald also has his self-interest that he works for. I don't think Kent has any self-interest other then helping his King.