I agree wholeheartedly, and wish I had received such advice when faced with a similar situation some years ago. If you are in a 2:1 minority and your most important aims & goals are not being considered at this early stage, it's not likely to get better without detailed consideration of potential future outcomes. I am being this negative because it sounds like you've already had some frank discussions about your differences of opinion, and you are having to go along with something you completely disagree with.