Mergers can be fun. I'm mostly kidding. They're hard hard work and most of the time fail. Companies are typically acquired for either customers or technology and little thought is given to the nurturing or even preservation of people. Many times there exists a my way or the highway mentality, especially when it's a large company acquiring a smaller company.
How do we play this game better? How do you thrive in this new environment? Having been through it a few times, I've boiled it down to 3 things as guide posts on the people road.
Take care of the people, the products, and the profits - in that order.
Identify leaders who can be culture bearers - Find the people in the acquired organization who have the ability to lead and are already somewhat aligned with the culture of the acquiring organization. Give them some responsibility in the integration that they can be successful at. People will start to follow and values will be reinforced.
Look for ways to bond the teams and measure it - Celebrate wins and ask for people to participate in the process to come up with solutions when you fail. These are the things that bond new teams together. The more wins you create, the more people will feel good about the situation. The trials create lasting bonds if the leaders can bring the people together to create a jointly owned solution. It's not hard to measure engagement. If you baseline people's engagement level around the goals of integration and pulse survey it you can easily get a sense of where people's heads are at and whether you're making progress or momentum is slipping.
M&A integrations are never easy and many of them fail to live up to the expectations of the acquirer. If you get the people part right the other pieces will start to fall into place. As Ben Horowitz says in his book, "The Hard Thing About Hard Things", "Take care of the people, the products, and the profits - in that order."