He can, if he wants. Scream is known for his flicks, not his tracking. I prefer to track a head and then do a short burst, most people prefer to do a quick flick and then spray.
It's just the way I play, and 90% of the time my first burst will be enough. Yeah, it's slower, but it's consistent and since my reaction time is pretty okay, it's not like I end up tracking for 2 seconds before I shoot.
There's quite a few pros who play like that as well, like rain. When he seriously goes for a target, he hits his shot because he doesn't just flick as close as possible, he tracks and shoots for perfect accuracy.