The biggest challenge with acquihiring is retention. Allowing the acquired team to continue what they were doing is the only somewhat foolproof strategy to deal with it. It's a question of pocket depth and expectations. How much will the new team contribute to the "home" product? If expectations are too high chances are that much of the team won't stay and the acquisition will turn out to be a waste of money. With lower expectations however, continuing to fund the project in question can be bargain for getting a pool of in-house consultants to occasionally tap into for the "home" product, if they are really as good.

And even if retention wasn't a problem at all, skilled people are not inherently skilled, they need to keep challenging themselves in their area of expertise to stay sharp. If the "home" product was failing to foster in-house expertise before then chances are high that it's a problem based on culture and priorities and experts injected from outside would quickly lose their edge. Keep them on the project they became experts on and they stay experts.