Good point, Tribes is great in many ways (non-hitscan weapons are much easier to see from an outside perspective, and you can usually see the big grabs coming from a few seconds away which makes the camera work easier) but it suffers from the fact that you have a massive team of people who are rarely in the same frame as one another. Unless your caster is a super-human or you get really, really good at camera work, it's going to be very difficult to both keep a thread of the important things that are happening and catch all of the impressive individual moments. It might fare better as an edited program, that way you can be certain to catch every important action at once, or maybe show the coordination in picture-in-picture.

That's one reason why I like SCII for not having most of these problems, because it's rare that there are multiple things going on that you have to pay attention to, as there is normally only one focal point of the game during combat. The rare occasions when this isn't true (a multi-pronged attack, or multiple drops), the fact that the spectator has to flip back and forth (literally the same thing that the player who is pulling off the multi attack is doing) to catch all the action makes the micro all the more impressive. But it's really hard to show two players on the same team doing something equally important and equally impressive when the gamespace doesn't allow you to have them both in the frame at the same time.