Not that it helps, but I can confirm that the Gen 2 Legacy H4 engines will run well enough to move the car on just two cylinders, and apparently the six cylinder ones will just about cope with three not firing, or indeed with broken conrods or missing spark plugs.
I know the first from experience (duff coil on one of my old 2.2s), luckily not the second. But there are some stories from the Australian forums of people limping home over 200km with fewer than the usual number of cylinders contributing, or indeed with no coolant. Rectified when they got back and went on to run for another 100,000km with no issues.
I do like my Subaru Legacys

- I've had three 1996 Gen 2s: 2.0 twin turbo GTB, 2.2 NA manual estate, 2.2 NA auto saloon (on LPG) and currently have a Gen 4 3.0 Outback (converted by Simon)