JRRT was an unlikely author. His intent was not to become an writer, it was an accident. The material that comprises the Sil, UT, BOLT, HOME etc are bits and pieces that JRRT tinkered with as a diversion, pre-hobbit years. In a true sense, his affinity for linguistics was the true impetus for his writing output at this time. He created languages and needed a context for them to exist in. He had to invent it and like early tales in other languages of fairies, dwarves, dragons, magic wizards, titanic struggles of good and evil, all that kind of stuff.
The bits he wrote to support the underlying linguistics at this time did not alway aggree with other bits he had written they were exercises in using his new toy and JRRT changed his mind often over the years as he tinkered with it. Post LOTR he promised publishers to make sense of the "notes" and fragments that were to become the Silmarrillion, but never did much til his death other than move papers around and organize into "piles". Chris took the task of reading everything and with the aid of some ghost writers completed the Silmarrillion and it was released. Years passed and Chris eventually worked his way through the absolute mess that the unpublished work was in, and has been doing his best to get the text to the public, with attendant commentary. It probably is no easy chore indeed....vast sections of text differ, names and places changed; A real beotch to basically make sense of it because a lot of it was in fragments.
I am looking forward to picking up the children of hurin - top rate tragedy therein! If it is handled well, it could be a very good read.
I was impressed with the writings of Herbert's son. The volumes that I have read were quite satisfying to read. Just an opinion.