I've been reloading since '65 and have well over two dozen manuals and twice or more that many pamplets. I've never had a blooper, skipped or double charge, never blew a primer, never a KABOOM! For the first five years I had a single manual (Lyman #43) and never felt I was handicapped in any way. I only got my second manual because of new powders that had been introduced.
Consider any manual as infallible and you're going to be in trouble. Follow the ONE rule of starting low for the powder and bullet weight you're using and slowly work up to book max unless you experience pressure signs early and back off if you do. Do that properly and it won't make any difference what manual, specific bullet, OAL, case, powder lot, primer, etc you use.
The basic instructions most manals have in the front are all good, none of them have anything important that the others don't include. Meaning if you can read and follow directions extra manuals won't add much safety and if you don't read and follow instructions a dozen manuals won't make you any safer.