Is there anything preventing the employees/founders from just immediately selling the Marin stock for its cash value? It's a public company so it should be trivial to sell for very near the same value given in the deal.
having been involved with a few acquisitions in the past, usually the terms of the deal have a lock in period where you can't sell to aid in retention. then you add on top of that new retention grants to handcuff folks as best you can.