Currently, I don't know for sure what the game considers "correct" actions for the engineer unlocks. There is some guidance on the forums, but it would be helpful if the language used to describe the engineer unlock requirements ("You gained access to Hero Ferrari by completing 10 surface conflict zones.") was #1) accurate (my understanding is that it should read ""You gained access to Hero Ferrari by completing 10 low-threat surface conflict zones.") and #2) correlated to a metric tracked in your player statistics (such as "number of completed low-threat surface conflict zones").
Ditto for "Complete 10 Restore or Reactivation On Foot missions", etc.
Ditto for "Complete 10 Restore or Reactivation On Foot missions", etc.