From an ecosystem perspective, acquihires trash the funding landscape. And from the employees’ perspective, as an investor, I’d see them being on an early founding team as a risk going forward. But that isn’t relevant if the individual pay-off is big.

But since they own equity in the current company, you can give them a ton of money by buying out that equity/paying acquisition bonuses that are conditional on staying for specific amounts of time, etc. And your current staff doesn't feel left out because "it's an acquisition" the way they would if you just paid some engineers 10x or 100x what you pay them.