Sorting Data Table (league table)

I have a mini-league scenario and with the results I have input, TeamB's overall results puts them in a superior position to TeamA but the league rules state that, when A & B are on equal points, the TeamA v TeamB result counts first...therefore TeamA finishes first.
How do I get the sort function to ignore the normal GF and GA columns and look at that result?
Similarly, what if there were 3 teams on equal points, how do I sort them by the results of their 3 games?
I'm flummoxed!

I suggest you create a helper column that looks for 2 or more teams on equal points.
...............................
teama.....15............15
teamb 13.............13.000001
teamc......13.............13.000002
teamd......12.............12

that applies the rules to find out who is truly higher. In the example above teamc is second, so in a second helper column sort the first helper column using =large(columnrange,1) =large(columnrange,2) etc and formatting as integers.

forgive my ignorance, but I'm not getting my head around the problem at all. I do know that I would require further columns to sort the data, but the only way that I have thought of would be damn ugly.

Is there any chance that you could insert your solution onto the sheet that I uploaded and re-post it?