only the conclave seems to research at 150% - the 3 towns and the village show +100%.
You see the 150% on the conclave because that conclave has a Cloister in it. The cloister is boosting research by 50%, including the +100% from the AI's difficulty level, so you see that bonus as +150%.
Then there's something weird going on with the difficulty levels on opponents ... because I'm running into this same general situation on Beginner difficulty ... the AI expands crazy fast ... and researches technology they shouldn't be able to get to at really early levels of the game. The AI in the early game just tromps everything ... so now I only play with two or so opponents on a huge map so I'll have time to do fun stuff before I get my rear end handed to me.
If you can provide a save I would love to check it out.