[aznatama]

Logically speaking, think about what the oil is used for... Lubrication. Why do some engines is thinner or thicker oil? Tolerances and materials used in the engine.

That being said, thinner oil flows into smaller spaces easier, but doesn't protect as well if tolerances are larger.

ATF is pretty thin. Used in auto transmissions that have tight tolerances and lots of moving gears/parts just like an engine.

In short, at the end of the day, just pull piston, check for abnormal wear, and if none, call it a day. All this talk about compensation is just for peace of mind. Most likely you won't keep the car past 100k miles anyways.