Non-Diversified Portfolios?

I have recently been listening to rotowire's Fantasy Football podcasts with Chris Liss. I find Chris to be incredibly knowledgeable and often use many of his ideas and thought processes, but I find this statement from his recent blog named My Portfolio to be flawed

"I've drafted six leagues over the last couple months, and figured I'd put them up side by side to see how the portfolio looks as a whole. As you'll see there's a lot of overlap, and that's by design - both because I like the guys I like, and because it's far better to have a big stake in a few players than a small stake in everyone in the entire league - in which case, you're always rooting for and against everyone."

There is significant downside risk to this idea, especially if the big stake you have is in players at the top of the draft. With Injuries playing a large part in fantasy football, taking a big stake in a few players could crush many of your teams. In this example, Liss has Pierre Thomas as his #1 RB in 4 of his 6 leagues, so he is putting lots of risk into the fact that this barely proven RB is going to 1 - Stay Healthy, 2 - Continue to be the primary back throughout the season. I don't think this is the optimal idea when it comes to fantasy leagues in which you believe you have an edge, I think more diversification is ideal. If you play this many leagues and don't believe you have an edge then by all means go ahead and blast away at loading up on a single player, but if that is the case, I have to ask why you would be in that many leagues to begin with.

Don't get me wrong, I think in the later rounds, when you are buying lottery tix with a smaller shot at breaking out, it is fine to have a bigger share of the same players, because of the positive effective of holding one of these breakout candidates, because the downside risk is almost non-existant..........so go ahead and grab Chris Henry in every league and LeSean McCoy in every league............but at the top, if you play to play 6 leagues and draft a top receiver in the 1st round of each, I would suggest an even spread of Fitz, Moss and AJ.............but that is just me.