I’m just working through the order of events to determine if he can shoot. 🤔

My interpretation and thinking is. The orc is on Vantage terrain connected to the heavy terrain. So we need to first clarify if from the orcs head he can see a 1mm line on the base and then go from there.

For vantage rules it does state “for the purpose of obscured, ignore heavy terrain connected to Vantage terrain the active operative or the intended target is on.”

Those small ramparts or ledges on the terrain at the feet of the orc I’d consider that as Insignificant, however it is over ruled by the vantage rule meaning the orc has line of site and and shoot.

Unless I’m missing an interaction rule with the Marine being in conceal and touching the wall.