This approach requires

1. a _huge_ amount of trust and respect for the acquired team to not meddle/interfere, and

2. a huge amount of restraint to not force the acquired team into conforming to whatever standards and norms are present in the acquiring team.

Both of these are exceedingly rare.

I'd say this is accurate for the most part but they bought the first company I worked for out of college and they really tightened the screws on our benefits packages under the guise of "unifications" with their existing stuff. They ended up moving me to a high deductible insurance plan which was absolute nads