Phil, I'm sure practical stuntwork limitations played a role in how Greengrass shot the scenes - Damon's an athletic guy, but there's no way he could keep up with the trained fighters brought in on these films. But I also think Plink is onto something when he says that viewers don't necessarily need to follow everything. This approach is certainly not without controversy, and other filmmakers have shown the merits of a more visually organized approach. The gold standard of this opposite approach, I feel, is Michael Mann. Watching the bank robbery in Heat or even the industrial yard shootout in Miami Vice, I always felt like I had a good handle on where everybody was and just the whole geography of it.
And going off topic for a second, I dare anyone to argue against the notion that the bank shootout in Heat is the single best shootout in the history of cinema!!!
But anyway, I'm saying that Greengrass's approach sure ain't for everyone, but it has MERIT and an aesthetic underpinning deserving of respect. The guy's a real filmmaker, and his track record is just about perfect. Sunday Bloody Sunday is one of the saddest and most intense docudramas ever made. Same goes for United 93. The Bourne movies have shown he can also do "commercial" with the best of them too.