One more factor to consider is distance! Especially for that switch loop. The garage is powered from the house and the light (on the garage) must be powered from the garage and switched from the house so that means the wiring for the light has to travel 3 times the total distance (from house panel to garage, back to the switch in house, then back to light on garage)
How far is the garage from the house?
Also the switch loop is the same wire coming and going carrying the same current and in really should NOT be counted twice as a current carrying conductor. Some inspector's might not agree so correct me if I am wrong! But if you do please tell me where in the code it says different.
Answers based on the mood I am in when you ask!