As far as I know Lucas didn't have to call all the actors back to reshoot half their scenes in ANH like he did on TPM (And the other two). Because ANH's problems were all down to pacing and 99% of the ground-breaking FX and wonderous music being missing, the performances, story and setup were all sound.

I've done the best part of a long-long cut of the ANH workprint with any and all material added back in (40 minutes-ish). It slows the pace down massively but it's still an enjoyable film because the material is just plain good no matter how you arrange or edit it.

TPM material was flawed from the very deepest core of it's inception. No amount of skilled editing is gonna pull a 1977 out of a 1999 and I think that's was why the blood had drained from all their faces after watching that TPM rough cut.