They are currently fully performance recorded, so by a combination of EBVs, easy care traits and conformation. However, I am considering cutting the sheep back and having an easier life which may mean not recording them properly any more.
I think mob breeding is a great way to create a setting or context which reduces work and at the same time can help your breeding/genetics improve.
Maybe using more than 5 per 100 will reduce the need to identify/ record who is the top 5. I'd just be cautious about not favoring single born tup lambs.