Because of the many actors we have in our main title sequence, we have
roughly two seconds in which to show their faces (the minimum SAG will allow).
If you show someone in action, you won't see their faces well enough to
recognize them, and there isn't enough time to do any kind of action.
Now, we could, as stated, do both...we could show some action on each
character, and then a closeup. But the opening title sequence as it is now
isn't long enough for all of the actors. So our choice is as follows: 1)
exclude some of the actors, or 2) make the main title longer, and cut time out
of the episode to compensate.
Those are the ONLY two options.
There is a point where reality and art intersect. This is one of them.
If we're going to show their faces, then we need to show them in closeup.
And there isn't time for anything else.
jms