This sounds to me like your sales team doesn't believe the target market is big enough and/or the right market. It's hard to believe in a product strategy unless you agree on who it's for, so the first thing I'd do here is to get everyone aligned on who you're building for & why, and then articulate why your strategy is the best way to win in that market.
We leave it to each team to figure out what helps them balance flexibility with clarity to achieve their maximum speed of execution.
We do our best to have a common language around goals, strategy & measuring progress, but largely leave it to teams to figure out how best to build & ship given their own goals, strategies & roadmap.