Confirn, also with Stryker's crew (Marines modul). If Styker is occupied with original crew that Stryker is fully operational (somethime fire smoke shell), if occupied with another crew, they sit as passenger and Stryker is still Dismounted.
It's terrible, if I have one destroyed Stryker with health bailed crew and second Stryker without gunner. If I can exchange crews, second Strykers is still dismouted.