Put all of the RAGBRAI material into context. They also have paragraphs about recumbents and riding in pace lines so they're not just picking on tandems.
RAGBRAI is a huge ride and attracts a lot of riders who have "questionnable" skills. You need to be aware of whose around you all the time. As long as you ride your own bike with reasonable caution, talk to the riders you are passing to let them know you are there, look behind you before changing lines and don't expect everyone else to do the same, you'll be fine.