Today much of society is filled with specialists, and when everything works correctly then a society full of specialists is more efficent.
Like in the photo below, a specialist can shoot an arrow and make a bulls eye 98-99% of the time. However the generalist can hit many areas on a given target. A specialist might be able to preform a certain medical procedure extremely well, however if the guy has a flat tire on his way to the apointment then things go up in flames.
The generalist has many diffrent skill sets, although even when he/she is operating on their 'A' game the best they can do is maby only 75%. So maby they can preform the medical procedure, but they sew you up in such a way that you will have a scar, however even if they do recieve a flat tire on there way to the procedure then they will proably be able to remedy the situation (of course their tire changing skills are a far cry from a 'pit' crew) but the job will sort of get done.
I once met a person that told me that the make computers for a living (I intend no disrespect) come to find out the person was just an expert at sodering the circut boards that go inside of computers. Specialists spread there jobs over many people, so instead of one person being able to build a computer every 10 days...there is 100 people turning out 5 computers every day, but if one person does not show up to work then 0 computers are mad even though 99% of the work is being done.
I was able to see the flaws in this sort of system a few years ago. I heard that beef cattle that were raised in the state of say Iowa were selling at a higher price, the reason for the price increase was that cattle feed grown (say) in the state of Texas was hard to come by due to a lack of rain in the state of Texas.
The following picture is interesting. It shows that a generalist and a specialist might be on the same level, but they see things differently. I think that it is interesting to note that 'committees' are formed to reach a level of expertise...but it can be extremely difficult to replace a coordinator. On a similar note, machines can replace specialists...but as far as I understand technology has yet to have reached the point where a machine can replace a coordinator.