For what you're proposing to work, all of the tags would need to be checked and set prior to import.
Why not try defining a holding place, a folder somewhere that all your 'incoming' music files will sit in until you've checked their tags and quality.
Have MC watch that folder. Any music placed within that folder will be imported into your library.
There are many and varied ways to handle these files, the easiest probably being a recently imported smartlist.
Personally, I have excluded such files from my main Audio tree and set up a view scheme that lists only the files in the incoming folder.
That view scheme has all the panes and columns I need to get the tags right on new audio files. Once that's done, select them and rename from properties to move them to their final resting place with the rest of my music, which automatically makes them available in the main Audio tree.
So simple, so try it
if the files from a multiple artist album are not already in the same directory, (beats me why they wouldn't be) you can force the issue with MC by simply selecting the files involved and setting the [album artist] tag to (Multiple Artists)
After doing that, a rename from properties, will place all the scattered files from that album neatly into a single folder of their own at a place of your choosing. You don't need to worry about where they are, just decide where they're going, set the tags right and then tell MC what you want. It will take care of it for you.
99% of the time, it really is that simple...
Import > Tag > Rename
If you want the rename process to take the [disc #] field into account, a database expression will make you're life so much easier, and if you need help with that, it's OK to ask.
The thing with us and our media files is that at the basic level, we all want the same, you know, artist in the [artist] tag, stuff like that, but you don't have to delve much further than that to find that many many people develop many many different work flows.
Did you know that you can set file tags by dropping them on tree items? I know about it, but in all my years using MC, I've never used it, but I've read posts in these forums from people who wouldn't tag any other way.
MC gives us acres of space to play in which allows all those different work flows to exist and that's where the learning curve comes in. You need to first think about what you want, then learn how to get it.
We're that used to being on rails with other software that quite often, the first stumbling block is actually thinking about what you want, after that, always be prepared to learn shorter routes to your goals. That 10 step list posted a few posts back has way too much redundancy. I honestly cannot remember the last time I used an external tool to get a file tagging or renaming job done.
I think I may have typed for too long... if you have any questions with regards to smoothing your work flow, just fire away
-marko.