Given that it is extremely easy to resequence tracks in a Playlist and in Playing Now, and that Views give you complete control over the sort sequence, you are going to have to provide much more information.
If you know your friend's User Name on the forum, or can point us to threads where s/he asked for help, that might provide some clue as to the issue.
Because basically, if your albums are sorted by track number, and you add them to Playing Now (for example by right-clicking an Album thumbnail and selecting "Add to Playing Now"), then they will be added to Playing Now in Track number sequence. Unless you have settings to say otherwise.
The Sequence Number in Playing Now/Playlists is just a way for MC to remember the order that you want to play files. If Playing Now/Playlists is still sorted by sequence number because you haven't re-sorted it, you can even drag and drop files to changes the sequence. Both are just a list referencing media files.
So, how do you add Albums to Playing Now/Playlists?
Please confirm which Sequence order/number you are seeing? Where are you seeing it?
Is it just in Playing Now/Playlists?