When I first set out touring, I carried a heavy load split across four panniers. Over time (usually as I was struggling up mountains) I threw away various things that I wasn’t really using. I then cut down to two panniers, before making the shift to bikepacking bags.
There are five bags on the bike. The three major ones are the seat pack, the frame bag, and the handlebar roll. Supplementary storage is provided by the handlebar accessory bag and the top tube bag.
The following link leads to a breakdown of all my gear, with weights provided.
Cycle Touring Sam 