Starcraft 2 : 3v3 and 4v4 Structure placement wisdom

In 3v3 and 4v4 I thought building structures at the choke was a good idea. I soon realized I was wrong. If they rush, they rush on one player. That puny choke is never going to hold. So the better idea imo, is to build the structures AROUND the harvesters, making it hard for them to kill the mineral line. And giving more time to your allies to send help, and myself time to make units.

All the while protecting my squishy harvesters......for a few more seconds anyways.