In risk analysis, do you prefer working as a group or single?

There is a saying that two heads are better than one but nothwhistanding the possibility that one head may also be good than two. From the perspective of portfolio having multiple investment source is good in spreading the risk. Thus if you have only one (single) investment and the market returns or interest change significantly its impact will drain or decrease such investment but if you have multiple the effect on one can be covered by the remaining sources henece in risk anaylsis is better to work in group.