More dispersed teams often outperformed “co-located” teams.

I don't read it as "often". I read it as "sometimes":

Virtual teams can outperform face-to-face teams.

A 2009 survey by Cisco of thousands of teleworkers found 69 percent said their productivity was higher when they worked remotely and 83 percent said their communication with other team members was either unaffected or enhanced by being dispersed. And in 2009, a research team led by Frank Siebdrat assessed the performance of 80 software companies around the world and found that more dispersed teams often outperformed “co-located” teams.

Siebdrat and his colleagues said the most important factor in the success of a remote team was having processes in place to make sure each member contributes fully, including adequate support and communication. Other good practices include scheduling time for virtual camaraderie building, including chatting in an informal context (see point 9).