Aquihires can be very destructive.

You end up with either the whole company, or you piss off the people that you wanted when you fire their co-workers. It also pulls in an almost complete graph of employees who are isolated from the new parent company.

Its much better to pull off the people that you want, and get them to join willingly, as they tend to adopt the culture/learn better when in isolation.

Poaching can be done quietly and cheaply, acquihires get everyone publically.

I suspect this would work in a lot of cases if you can find out who the key engineers/strategy people in the company are. But working that out is probably the hard part.

If you have the money an acquihire guarantees you get everything. But then you still have to work out who those key people are after the fact and make sure you keep them happy.