I think the OP posted an excellent question, and many of the answers have been excellent as well!
Let me give my opinion..actually, the Najdorf and Caro are two of my top opening lines in tournament play. I consider that I understand the Najdorf and the Caro about equally well (or badly!).
I DON'T consider the Caro-Kann to be a drawing weapon, per se. There are ways for Black to steer the game towards a draw if that is their goal, but there are definitely ways to unbalance the play (positionally more than tactically). Najdorfs very often lead to drawish positions because the theory is often so lengthy (for example the Poisoned Pawn or Vallejo-Pons Variation). If I want a draw, I've found it is much easier to get by playing the Najdorf actively but not letting things get "out of control," than by playing the Caro.
Let me state right here that if I know for a fact that my opponent likes to play some kind of anti-Sicilian, I'm playing 1...c5! The Alapin, Moscow, Smith-Morra, Grand Prix, etc. don't scare me. I have great confidence in outplaying my opponent in these systems. The winner will be the player who understands chess better, that'll be me.
The main thing in my choice would be my MOOD. Do I want to force the play or "play off of" my opponent? I am a natural counterpuncher, but have rounded out my play more over the years. I don't mind reacting to my opponent.
The other top consideration would be my opponent. If I know their repertoire or their style, I can prepare something unpleasant and catch them. If I don't, the general rule that younger players like sharper lines and older players like slower play is more accurate than not. As an aside, I have noticed that even older players who like to play sharply don't calculate so wonderfully...
[A lot of adults are afraid of playing kids and teens, but the weakness of youngsters is that they are generally very predictable and sitting ducks to prepare for. When an adult would be wary they're walking into a prepared variation and maybe deviate, a young player will blissfully keep walking the plank...And I'm even talking about players rated 2000- or 2200-and up. Young players don't react as well to unexpected opening play, and they can't alter their style of play easily.]
Some interesting posts above about tournament strategy above. If I feel I NEED to win regardless of risk, I will play in the most uncompromising fashion I can, which could be EITHER the Najdorf or Caro (as well as other things)! Depending on my mood and my opponent, as above.
A lot of games can be won in "Matador style"...bait the angry bull...
Thanks!