As the leader, you need a framework to assess your leadership team. Make sure you set your expectations for them to be 1) Functional experts 2) People leaders 3) Business leaders.
One of the biggest misconceptions about how leaders talk to people is that they are supposed to be "nice." It's not about being nice! It's about using the right tools to come across clearly and not shut people down - for some that can be harder than it sounds! Use these tools: 1) Manage your tone 2) Frame it so they can hear you 3) Be specific.