The WM Flash Jacket, Patagonia Down Sweater, and other similars are basically "fleece-killer" pieces, not stand-alone winter parkas. The WM Flash, for example, uses ~3 oz of down; by comparison, the FF Volant uses ~9oz of down. No question which one you'd rather wear while essentially stationary in cold weather.
I feel that an insulated hood is mandatory in those conditions. The Volant is available with a hood, probably adds ~2-3oz overall to the jacket, I'm guessing. That would take the Volant to 25oz; the Frontpoint is 30 oz, but uses 13 oz of down. I'd prefer the extra down for what you're talking about. I'd also prefer more length in the jacket/parka. Patagonia DAS parka is a consideration, 26oz, but I personally wouldn't find it quite warm enough...
Edit: Just noticed that even Montbell refers to their Alpine Light as midlayer warmth, compares the AL parka to a fleece. Also, the Volant is the only baffled jacket of the ones you mentioned. Baffling certainly isn't necessary, but it does certainly add a noticeable degree of warmth. My big down vest is fully baffled, and it keeps the heat in like nothing I've worn (I have an old Marmot Parbat, too--pretty nice, but the vest is warmer.) Actually, there was one small section (1/4" or less?) of the vest that didn't get filled (where I joined the hood to torso), and I had a distinct cold spot there, nothing but warm everywhere else. Point being, if you can find a baffled parka for what you're talking about you'll stay warmer.