Doesn't answer your question, but gives some insight...

https://forums.matrixgames.com/viewtopic.php?t=412530

Thanks.

And its just hit me....a package is a strike on a target(s) that uses "combined arms" aircraft (aircraft with different capabilities used to strike targets and protect the bombers as well as the rest of the package). Heres an example of a package;
Attack/bombers to strike the target, escorts to defend the bombers from air attack, EW aircraft to jam enemy radar, SEAD aircraft to suppress enemy SAMS, also DEAD aircraft loadouts to destroy them and AA guns combined.

In the game a package can just be a land strike mission with 4 bombers with no escorts of any kind attached...thats it, thats not a package though. Might as well just be a mission. Just a suggestion.

I use packages to organize complex or large groups distributed across areas. If you use packages and ToT properly, large and complex missions can be easier to understand if the participating aircraft are on multiple bases.

With that said, I rarely use them. I tend to run smaller flights in missions specifically to avoid complexity and stress.