One interesting thing about the Too Much Johnson fiasco, of which there are accounts in several Welles biographies, is that it marks the first of many times throughout his career that a Welles project collapsed at the film-editing stage. In this case, he apparently tried to do all the editing himself and realized too late that he had bitten off more then he could chew.
Peter Tonguette’s book Orson Welles Remembered has accounts from several different editors who worked with Welles at various stages in his career, and they all claim that Welles never did any physical editing on his pictures, merely oversaw the editing that they themselves did (although at least one of these editors says Welles liked to give the impression in interviews that he had done all the editing himself). The man who edited the battle scene from Chimes at Midnight claims Welles was not even in the country when the sequence was completed, but gave his approval later. This same editor says that Welles made him edit and reedit the scene where Hotspur leaves his wife to such an extent, that the scene was eventually spoiled from overediting.
It would be interesting to have a documented list of what scenes in what films Welles actually did the editing himself, what scenes in which he supervised the work of others, and which scenes to which he merely gave his approval later. If I’m not mistaken he attempted to edit both Arkadin and TOE himself and in both cases could not get the job done quickly enough to satisfy the producers, who removed him from the film in both cases.