It can be argued that the cornucopia of talent makes his managing job a bit tougher. He's dealt with a revolving door the past few years and repeated band-aids, and some pretty big personalities. Every single year they've picked up free agents -- just not the right ones. They've had glaring weaknesses each year, typically either starting pitching or relief pitching. Much of this can be attributed to them trading prospects for years, and depleting their farm system and not continuing to build what used to be a premier farm system (early 90s...go figure.)
Joe Torre is great because he puts his talent out there and lets them do their thing. He doesn't micromanage and do weird double-switches and shuffle his lineup for no reason (LaRussa), nor does he throw tantrums like a buffoon (Piniella, Lasorda). Importance to a baseball team: Players - 90-95%, Managers - the rest