I'm late to the party for Subaru Chat, but having owned 6 different Subarus with 6 different drivetrains there isn't really a "rule" for these and "symmetrical" means nothing but a marketing slogan. The worst I had in the snow was my SVX with the aforementioned 90/10 torque split. The best was my XT coupe, with a lockable center diff and 50/50 torque split and weight distribution. It would pivot like a tank and was unstoppable in the snow. Absolutely wild to drive through snow deeper than the hood level and have it blasting over my windshield. The trade-off was that it ate CV joints like candy.
I had some fun times in that car.
I had some fun times in that car.