When deploying extra followers from a crop circle action, I'm not sure which meeple count as followers. The CAR states that players may take one of their own followers from their supply and deploy it next to another of their followers already on a landscape tile. It also reads that players must deploy the follower to a feature which already contains a follower of the same type (farmer to a farmer, thief to a thief, knight to a knight).
This would exclude the builder or wagon, I suppose. But not the big follower... But the mayor would count as a knight when it's in a city. Does it, however, count as a follower in your supply?
Which meeples can be placed onto the board next to another follower, as the result of an action from a crop circle?