Stats can prove whatever you want
I seem to recall that the reason that Harriers weren't allowed to fly over London for fly pasts in recent years was that the risk of engine failure was too high given the chances of landing in a heavily populated area. Not helped by Harriers not gliding very well (JF feel free to comment as appropriate!) No such issues of course for Hawks.
Getting the lift fan/swivel nozzle mechanism to work with two engines would have been interesting.
To keep things common that probably drove the single engine design across all 3 variants.
LO - With partner nations involved at the Programme Office and the Development Test sites feeding back info to their respective governments at least they don't have to rely on media reports or LM press releases to make decisions on. (Whether they listen is another question!)