And JMS has retrospectively said most of the original novelisations were toss. Voices was particularly bad, being written in about 27 days to cash in on the series popularity. Apart from books 5 and 7 and the subsequent trilogies, I don't think JMS had much consultation on the novels, and hence doesn't regard them as canon.
This is as much due to the poor quality of the writing as to the fact that all the books apart from 5 and 7 do not advance the plot, instead simply having conflict and returning it to the status quo at the end. Like most Star Trek books.
Writing quality is going to be a big issue. I'm guessing the writers of the Mongoose novels aren't professional writers (but then Mongoose can't afford them and they may well have reservations about writing for a licence like B5 that is not too high profile anymore).
This is as much due to the poor quality of the writing as to the fact that all the books apart from 5 and 7 do not advance the plot, instead simply having conflict and returning it to the status quo at the end. Like most Star Trek books.
Writing quality is going to be a big issue. I'm guessing the writers of the Mongoose novels aren't professional writers (but then Mongoose can't afford them and they may well have reservations about writing for a licence like B5 that is not too high profile anymore).