Gerhard, I try not to say too much about these old lines but since you ask ...
I've been working on getting them fixed in some reasonable way ever since I've been on Geni, but it's very hard. We have to keep the fake profiles, or people will assume we don't know about them, and add them back. It would be good if none of us were connected to any of the fakes, but the best we can hope for right now is not to be actually descended from them.
It's very hard to cut the bad lines. You have to merge all the duplicates, and keep merging the new duplicates. And you have know where the fakery starts, and document it with good sources. You can't just start slashing.
We had someone who cut 80 something connections in one marathon session, but they did it arbitrarily, in nonsensical places, and they didn't document the reason. That means that dozens of other users think we just didn't have all the information, so they started adding new duplicates.
Any time you cut a connection the users who agree don't say anything, but a small number of users scream because they are no longer descended from Jesus (or whomever it is they want to be descended from). Just this week we saw a user trying to defend a fake connection to the dukes of Normandy. It takes a lot of time and energy to argue.
I don't know about any Irish orcs. In fact, I'm not aware of any orcs on Geni at all. Can you give me a link? I'll take a look.
If you're descended from Adam and Eve (or King David), and if you're not Jewish, and if the line doesn't go through Paloma ha-Leví Benveniste, it's a fake. And if the line does go through Paloma, there is a lot of argument about whether it's fake ;)