If these "3 miners" are controlling the majority of the hashing power - which isn't too far fetched from how the things really are - we're literally talking like 10 physical individuals here - then yes, they get to tell the others what to do.
This already happened in the past and looks like Ver and AntPool are trying to make it happen again. And they know full well that it's not that hard to do:
>>> "Ver says he plans to step up lobbying efforts, especially in China which is home to the majority of bitcoin mining."
and again this lobbying^^ will only need to be applied to a few concrete individuals again because of the extreme level of centralization of the hashing power.
I see what you're saying, but you originally said that miners get to "impose their will". If Bitcoin miners have announced support for Bitcoin Unlimited and the market price hasn't crashed in response, what does that tell us?
This already happened in the past and looks like Ver and AntPool are trying to make it happen again. And they know full well that it's not that hard to do:
>>> "Ver says he plans to step up lobbying efforts, especially in China which is home to the majority of bitcoin mining."
and again this lobbying^^ will only need to be applied to a few concrete individuals again because of the extreme level of centralization of the hashing power.