As the Jaguar has the same engine family as the Hawk, what do Jaguar drivers do when 2 get silent? Given that the Hawk is a trainer aircraft (albeit fast jet) and a classic direct mechanical/hydraulic flight controls system as opposed to the fly by computer type I would expect it's handling qualities to be nice enough and if sufficient control power could be obtained the Mk 1 pilot should be able to control it.
For fly by computer tactical aircraft that are designed to be inherently unstable if one of two powerplants go the other takes over, if both go you have the RAT or APU or backup power, if that all goes and you can't get the "d" cells from your flashlight (excuse me, torch) into the computer quick enough it looks like you are SOL. seams likethere should be a mode to allow basic control of the aircraft to give drivers a little time to get to a best jumping out point or to get the aircraft on the deck.