Need to sum scores from different teams

I'm having a problem construction a few equations for a score sheet that I've been working on. I am attempting to simply sum individual member scores that are part of a team and have it rank order and post the information. I can't seem to get it to work and am hoping that you folks might be able to help.

I've constructed a mockup spreadsheet with the data. I have highlighted the cells that I need help with. Please take a look and reply inline if you need any clarification or have questions. Thanks in advance!