Andrew,
The assignment speaks clearly about one component diagram and you know, it makes perfect sense, as in one diagram all the components and their relationships are displayed.
I think we heard in this forum about people who submitted multiple component diagrams. Try to search a bit....
I use Jude that doesn't impose a limit on the number of components.
About multiple stereotypes - The fact that MagicDraw and Jude and probably other tools allow multiple stereotypes show that it can bring value. Anything that can bring order in a standardized way is a good thing in our IT world

.
Just be consistent with the use of stereotypes.
Regards,
Dan