I've seen this time and time again. As you pointed out discussion is the key to solving differences.

It's a hard position to be in. As the Old Guard, when you've had the long nights and fought all the early battles, you might feel apprehensive when the New Guard starts questioning your methods and poking holes in your logic. The New Guard needs to be careful as well, because unfortunately, the company and the product as it stands today was created through many decisions; some ad-hoc, some well though through. You owe it to your new company to understand the history of the status quo.

The hundred million dollar question is finding a solution to ease the integration of the New Guard. As a company, once you've decided you need to hire, you have to integrate the new person and all of their collective experiences.

Thanks for the great post. It codifies some thoughts I've had on this topic.