They played against other players. I haven't done a TT tourney for awhile but that's always a better way to get points than dueling NPCs. There's a matching NPC in the Battlehall that will pit you against other players currently in the hall for tournament matches. That being said, there's a possibility that on top of that they were win-trading, but I'm not as versed atm to see all the signs but there are a few I'm suspicious of in those ranks, though simply being over 1780 isn't an indicator. You may also wish to blacken out names in screenshots, particularly in posts that allege wrongdoing on individuals as it can be seen as name-shaming/witch-hunting, which is against the rules of the OF.