When I compare AFFC/ADWD with COT, I don't mean in terms of style/pacing/events etc., I mean both are "unplanned books" fixing planning problems, and all three were pretty badly received by a good part of their hardcore fan base.



Not really. He had just four "story aggregates to resolve", three of those really not very complex. He simply made a big structural mistake after TPOD.

When he wrote TPOD, he firmly believed he had two more books to go (plus AMOL, the starting points, main events, structure etc. of which he all had developed early). With this conviction, he committed himself and put in motion events that lead straight to the the long planned starting points of his finale (the Cleansing, the race for the Lion throne, the AS coming to TV, sending Perrin south etc.), and this bit him in the ass later.

With WH, he made the mistake of opting for a short book (by WOT standards) not including the pre-Cleansing material from all story lines. His original plan was to deal with the four story lines in the next book, re introducing Rand around the beginning of act 2. It worked well enough for WH.

Then everything went wrong. As he began working on COT he first made a bad evaluation of how many calendar days he would need to resolve each story line and he also badly evaluated where the "core events" of the story lines happened (which lead to problems of balance between them) and he had this bad "good idea" to show the Cleansing from each story line, then from this turning point things picked pace and lead to the starting points of the finale (Egwene about to face Elaida, Rand going to AD with Semirhage captured, Perrin about to bump in Galad, Mat returning to Caemlyn where Elayne had just won the throne etc.).

RJ's method (abundantly described by Brandon) to build novels doesn't easily allow for big structural changes along the way. He wrote things completely out of order.. mid book key scenes (often just key dialogue in first draft, because he had no idea yet of the setting), then key scenes of the climaxes, then the starting points (prologue), then he worked on the "in between" key scenes and from there connected everything, eventually he knew where the tertiary material ought to go and spread it out as "unconnected scenes" or dealt with that as background events mentionned in dialogue scenes. Those layers involving events dealing with tertiary stuff and characters, RJ always added very late, once the primary stuff was shaped and he was rewriting each chapter in more final form, this time more chronologically. It's one reason why this tertiary "layer" is so absent in Sanderson's books: except for early scenes and climax scenes he had started to write in more final form it's usually not in RJ's outline or his drafted scenes (some of those Team Jordan rather found in his notes, some escaped them until too late and some found after TGS Brandon found ways to include in TOM).

So as he started COT RJ ended up misjudging where he should have made ellipses. It turned out Mat and Egwene needed far more calendar days and "events" than he hoped, and that cornered him with Elayne and Perrin who needed far less. He realized this very late in the drafting process that he should have made Elayne's and Perrin's story lines start only later, skip ahead after an ellipse. But he had already written their pre-Cleansing stuff, picking up where TPOD left them. Changing that would ruin his planned pre-Cleansing/post-Cleansing pivot around which he had organized the book, and would force him to rewrite two story lines from scratch and make major revisions to the rest, so instead he pushed some of the written material to what became KOD, and he reworked his post-Cleansing material to bring them to pseudo-climaxes instead of the planned ones. In the process, Elayne's post-Cleansing story line got expanded to stall things up, and Perrin's got a similar treatment.

He ended up covering about 1/3 of the story progression he planned to include in COT, spending much of the post-Cleansing time building to a more or less decent ending for each instead of the real ones, which became KOD's climaxes.

Instead of the LOC style (slow build up, sudden increase in pace/happenings from the mid mark to the end) we ended up with a novel that's in form typical of the first act of the bigger WOT books, only longer than usual, with some story lines unnaturally stretched out because he had to stall things up in them.

The novel was disappointing when it came out. The readers who like RJ's "slow beginnings" didn't mind that much, except for some irritation at a lack of the more entertaining acts 2 & 3 found in the previous books. Readers already irritated that RJ made his set up acts too long to their taste since the mid-series, and they're an important part of the fandom, reacted far more badly.

IMO reading KOD right after solves most of the problems, it now just lingers on too much and the "false" endings of COT coupled with the introduction parts of KOD aren't quite optimal, but you still can see the full book it was supposed to be.

So yeah it's comparable to what happened to Martin, except for Martin it wasn't fixing up a month or two of story time to get back on his feet, it was filling a planned hole of five years he had built to, but realized too late he couldn't work with. He had to create a book out of events he meant to happen largely off-screen, events that through allusions would have gradually explained the sudden character development and plot twists we found in the post-gap book. And it turned out he needed 10 years and two books to do this. A much bigger mistake than RJ made after TPOD, but structure-related like his.