You can make sure your round-robins will be properly ranked for the tournament stats.
Go to Menu > Manage > Statistics/Standings > Stats Model Editor.
Select Model for Teams or Model for players.
Set the information under the section called Ranking (bottom left).
You can have Head to Head as one of them.
Then select Head to Head model and set the ranking for Head to head under ranking section (Bottom left)
If the system has to go into a Head to Head stat to determine the Rank. It will look at the Head to Head model to see what to base it on.