Both are fine as long as you consistently make the play. It really becomes a matter of procedure vs technique. A procedure is something you do. A technique is how you do it. Fielding "procedure" would involve moving to the ball, catching it, transitioning to throwing, and then getting the ball to the base. "Technique" would be "how" a player's footwork gets him to the ball, "how" he fields it, and "how" he throws. Procedure stays the same for all fielders but the technique will vary depending on the strengths and weaknesses of the player.
Teaching one "technique" is only good for the players who have strengths that go along with that technique. I've always felt you teach the basic techniques but then let the players develop their own style. That's why every hitter has a different stance and why every pitcher has a slightly different set of mechanics. Jeter's style works for Jeter and Reyes' works for Reyes.
Every style has pros and cons.
As a side note, I'm assuming the kids are in high school. If you're talking about little leaguers without a foundation yet, I probably would emphasize just one, basic, efficient set of techniques.