While I can’t point to specific field marks, based on shape and proportions, all three birds look to me like Long-billed Dowitchers. Dowitchers are of special interest to me, so I’ve made a point of photographing as many known individuals (identified by voice) as I can. If you or anybody else is interested I can send you a pdf (9 MB) with photos of about 70 winter plumage dowitchers identified to species. Just send me an email to the address below.
As Alvaro said, the two species prefer different habitats, but for the San Francisco Bay area I would refine their preferences a bit more. Short-billed Dowitchers are typically found along the ocean side of the San Francisco Peninsula, and on the mudflats along the immediate shore of San Francisco Bay, as along the shell bar in Foster City. As you move back from the immediate shore of the bay into the tidal creeks and sloughs (Palo Alto Baylands, Shoreline Park in Mountain View, Don Edwards Refuge in Alviso, etc.), Long-billed Dowitcher becomes the dominant species. The mud on the tidal flats at the Foster City shell bar and the mud up along the tidal creeks doesn't seem that different to me, but apparently it is to the dowitchers.