I've looked through the past few pages on the forum and checked the FAQ and I believe I didn't see anything about this.
I have both the Fallout 3 GOTY and FNV UE, both purchased from Steam.
The TTW install goes perfectly (I think?), but when I go to set the load order in the NMM or FOMM, most of the FO3 files aren't there?

As you can see, all of the FNV files are available, but the only two FO3 files that are showing are Operation Anchorage and Broken Steel
I've used TTW before on my old computer using these same games, and it worked perfectly.