On this subject, there's a further point I'd make - this is a genuine question, I don't know the answer...
Talking about thrust not coming back from climb power in the level off, for example; in A/T systems with moving thrust levers, doesn't the fact that the thrust lever needs to move potentially cause a problem in that if the thrust lever is physically stuck (jammed mechanism, FOD in the lever slots, etc), the thrust can't retard even if the A/T is commanding it? Or does the A/T system allow for the lever position to be over-ridden if it detects such a fault?
On a system with non-moving thrust levers, despite the fact that other parts of the system could still theoretically cause an error, the potential for the stuck thrust lever problem is eliminated.