I always create a separate Timeline for each and all Assets. I do not gang them on a single Timeline. When one does this, there are often gaps in the Video, because the Audio is longer, maybe just an Audio unit, or two. Also, depending on the Audio file type, there can be Duration differences, just because of encoding schemes. Cannot recall the numbers for the blocks, but Neil Wilkes has offered that up in several replies to similar posts. One way around this is to make sure to have a bit of Black Video on the Timeline in PrPro, and let the Audio end maybe 1 - 2 secs. earlier. Note too, that if one is doing DD 5.1 SS AC3's, many players, especially higher-end ones, need 02 sec. to "lock onto" the AC3, so 02 sec. of silent Audio is a good idea, or the music might not be heard until a few sec. into it. Neil refers to this a "Black Audio," but it's really silence.
I just use Playlists to get the navigation that I require from the multiple Timelines.
Good luck,
Hunt
