How do I protect our product strategy from sales pushback? Our sales team doesn’t focus, and is trying to make our product easy to sell to anyone, rather that our target market.

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.