Seeing live games from sourcetv's don't always tell the story of what's really going on in the game, nor do the end game stats. You'd need to be on mumble to really get the full scoop of the decision making and synergy going on during the game. Since TF2 is very team oriented different players can bring out the best in other players depending on their styles. Some people prefer quieter medics because they prefer to main call like Plat, while some require medics that are more vocal to guide. It all depends on what compliments your pocket to play to their potential I think.
One scout might be the aggro scout getting all the kills and making plays, the other scout may be the passive one playing around the flank making sure points get capped. The aggro scout may appear to have way better damage/frag numbers all around but it's really just the role they're playing. Their role makes them look like the better scout. The passive scout with inferior numbers could actually be the better all around scout though. However the stats don't say so. This goes back to different medics complimenting their pocket. A good medic could make their pocket look good or bad. At the end of the day if your pocket looks amazing then your medic must be doing a pretty good job at keeping him alive to get those stats in. No glory!
Shade and tyrone are a pretty good example from the past.