I know this moment all too well. I've been on both sides of this one, and let me say - it's not as scary as you think.

If the new hire comes to the table with more to offer than previous hires, then it shouldn't be something you have to "sell". If you think you need to "sell" this new hire to your team and make great strides to prove his/her value to the team, you may not have the hotshot you think you do.

If your team is in it for the product, the vision - your vision, then they shouldn't be as concerned with the fact the new hire will be taking on more equity than they have. They should be on board with the idea that if this is THE guy to get things done, that they're that much closer to hitting the goal.

If you want to hop on a call and chat through the scenario and not talk about it in a semi-public forum, let's get on a call.