Never kept them myself but know a few people who do. They have all said that they are quite difficult to train ie. to get them to sleep indoors or stay where they should. They all did what you did but I think in a lot of cases the guinea fowl soon started finding their own roosting places and sleeping out. Some visited other farms and one man said that he didnt see his for weeks at one point, thought Mr Fox had eaten them and one morning there they were back in the yard! Guess they like to be truly free range. They are beautiful though.
Hope someone comes along who can give you more training advice.