I believe it’s complicated because there are really two playbooks:
Do you want to retain the founders and senior execs? I mean — really retain them? Or not?
If retaining the founders and senior team is not a priority — and it isn’t always — my learning is integrate hard, fast and soon. And make sure you have a strong GM or other resource to put in as head of the new acquisition as soon as possible.
If retaining the founders is a priority — you have to let them work the way they work, and surround them with help from the mother ship. And give them enough financial incentives to stay.
In my experience at least, the middle ground — semi-integrate, force the founders to change too much, not enough financial incentives — is the easy way to go.
And the worst way to go. You get the least of the benefits.