In the 135, an engine problem is indicated by multiple captions on one side or other of the CAD screen, clearly indicating which engine has the problem, as does the VEMD and T's&P's screen. The FLI needles have I & II on them to identify a good or bad engine and the VEMD screen will show low N1,Tq & TOT values on the left (#1) or right (#2) side of the screen.
There is a scenario that might actually be the complete opposite to which you interpret as "good versus bad".
The assumption is that pilots actually know how these things work.
Unfortunately history has shown the opposite in some cases.