Tagsource list is hard to manage when having many tracks

I find it very difficult to arrange the tracks in the tag source list.
Example: The source e.g. Discogs is showing a box set of 4 Cd's with 20 tracks per CD.
I only have a few numbers from these CD’s and the option "Title Sort" under the Utils button does not give a satisfactory result.
It's almost impossible to get the tracks in the correct position using the up and down button related to the e.g. Discogs source.
Some sort of line numbering in the right hand part of the source list would be very useful !!
But maybe I am overlooking an option.
If so apologies and please tell me where to find it or how to do what I want.

That’s, till now, the only minor problem I had since I am using MP 3 tag and I am already using it for a few years.