The meter for the FE doesn't read off the film. The photocell is in the viewfinder and and a hold circuit hold the meter reading when the mirror goes up. None of the Nikon does off the film metering (except for TTL flash in which case the FE doesn't support) it's just not the Nikon way.
1. When the + led only lit then over exposure by more than 1 stop.
2. When the + and 0 leds are both lit then it's over exposure from 1/5 to 1 stop.
3. When only the 0 led is lit then the exposure is within +/- 1/5 stop
4. When the - and 0 led are lit then it's underexposure by 1/5 to 1 stop
5 When only the - led is lit then underexposure by more than 1 stop.
That's how. It's resolve to 1/5 stop but only at the 0 point. So one can't say the FE is more accurate, It's more convienient with the FE I agree.
Alls I know is that that my FE has never given me the wrong exposure. It simply boggles my mind. I even shot it with Velvia at 40 and no problem. There's a very difficult, cave like building that we set it up on a tripod, I light metered for my large format camera and came to about 2.5 minutes, set the FE on there, and it exposed for 3 minutes. Compared side by side, the FE was better than I.