The idea behind Wikitree is to connect everyone together. Right now we have over 22,578,000 connected. because they are living I can't see your father or his family or who are the managers. But when you connect to the main tree you will see how you are connected to over 22,578,000 people.
There are many different way to look at them so this may be the reason for your difficulty. Could you get into a little more detail of your problem?