Get the 315s, and never look back.
I'm thinking you might want to give it a rest here.
By your own admission, you haven't had a good notion of what it feels like to drive an obstacle with lockers - never mind bigger tires. Now it becomes clear you haven't had the experience of what it means to drive an automatic transmission in an obstacle - namely with the right foot on the gas to control available engine torque, and at the same time with the left foot on the brake to control forward progress. Newsflash - lockers and left-foot-brake will control wheelspin. Very effectively, I should add. Don't tell me that wastes brake pads - it'll only reinforce the notion that you have no direct experience. Some of us have that experience and expertise. You're free to discount that expertise in favor of your own experience. But I'm not sure doing that will support the notions you brought forward.
As for your beloved alpine meadows, I've seen first-hand a situation (photo-documented on this very message board, by the way...) where there was destruction of a pristine alpine meadow (in Utah, so it might not count for you...) by vehicles with inconsiderate or irresponsible drivers. They got stuck precisely because they didn't have traction aids...
I encourage everyone to 'run what you brung'. Just be prepared to turn around when you didn't bring enough. Don't rely on the Landcruiser mystique to get you through safely, no matter what the flatlander says.
I got locker experience, down on the farm. In rocks, no, but I generally consider lockers as a "get out of trouble" device. Never needed them on 31s or less to get where I needed to go in Colorado, so suspect I'll not need them on 33s either. Thanks for the tips on driving an auto (even though I recall reading them back around 1975 in PV4), I've got some learning curve there, to be sure, but rather doubt that 4 plus decades driving a stick leaves me completely unprepared driving something that does the shifting for you most of the time.
I certainly agree, don't get in over your head or tear up stuff just to prove something to yourself. I've had to make that decision twice in Colorado, both times on Holy Cross. If that somehow indicates a lack of experience to you, that's cool, you're obviously sizing up a different sample of drivers than the one I'm in (or likely 90% of the rest of us are here.)
And I don't want to beat the horse on this one, most of the folks here aren't out tearing up stuff where they shouldn't be (as I noted), but why anyone feels the need to drive a pristine meadow when there's a trail next to it is somewhat baffling to me. I'm a Stay the Trail sort. Others feel differently and so long as Ranger Rick's not standing by, try not to make a mess if you aren't. No, you shouldn't be off the trail without the equipment to avoid trashing things in any case, I agree.