How about this? The strong points in the GFI & GFII was the attention to detail in depicting the Corleone family in the past. GFIII, basically set in the present time. Just doesn't quite hold the same interest.
One could make a case that I&II largely portrayed Vito and Michael in control despite the travails they faced. One had confidence that they would successfully meet the challenges they faced. However, in III, Michael's control seemed tenuous and the challenges he faced required help to overcome.
