trans cooler hookup?

Was wondering when installing an aftermarket cooler with the stock radiator cooler witch would you run through first. Someone told me to run through aftrmarket cooler first then through the stock radiator cooler, reson being if the auxilary cooler cools the oil too much then the stock radiator cooler will then heat it back to operating temp. Makes sence too me, but would like to hear your opinions, thanks

The other benefit is the radiator does not take the full brunt of the heat first, leaving more cooling available for the engine.

Is it even possible to cool the tranny fluid down too much? I've always been told to run the biggest tranny cooler possible.

Radiator cooler to aux cooler. That is how it was OEM and worked then and still does.