What are your steps to winning over the different senior stakeholders around the business around the product story that you're crafting?
Develop a facts-based point of view, including audience research and competitive intelligence. You're building a case for why the story is compelling to the audience, not just your senior leadership. If you don't have this, senior leadership (like all people) will go with their gut or feeling to how to deliver a strong story. Have a point of view and be ready to debate it.
During the debate, don't cave. If you believe in the positioning, try to advocate for it, and take feedback to improve it. I've seen senior leaders argue points more to ensure that the view is strong and has sound logic. So stand your ground, argue the case.
Ensure you incorporate feedback and advance the positioning. If there are arguments and tweaks based on pro-active feedback, keep it and document it, and keep a paper trail of decisions. Ensure/remind when decisions have been re-argued and try to move the positioning forward to agreement vs being stuck in circular conversations.
It will be a journey, but bring stakeholders along on the journey and it will be better for everyone.