In thousands of songs, I've never noticed Picard doing anything to the length of the files. I tend to manually review every album by running it through Picard and letting it handle the renaming and tagging. That structure used to be Artist/Year Album/Song. I've been less strict about naming the songs themselves. It's always at least track - Title, but sometimes Artist - Album - Disc # - is prepended. Eventually I ran into a situation where I had multiple versions of a release/album with different enough content to warrant keeping both, so now I throw a release ID number (if is exists) after the album name, and inside brackets, for the directory name.

It's a very flat structure by design, so I'm never quibbling about where I sourced something or what particular genre it is when I'm looking for it. That dramatically reduces the likelihood of duplicates too. Real metadata is better left to tags, since that's mostly what any player will see anyway.

If I'm having trouble getting Picard to recognize something it always because: musicbrainz.org is missing the release, doesn't have acoustic ID, or Picard preferred the album track when I'm trying to rename and tag a single or EP. Adding the release info and acoustic ID to musicbrainz is easy and I can usually use the info before the release is even reviewed, but often in trying to add the release I'll find the correct one and now I can help fill out the data about it.

I treat musicbrainz.org as MY metadata database. If a release is missing or has problems, I do the work to make it better. It's good digital citizenship and learning about their rules for releases helps me manage my server better.