Sounds like you duplicated the marines actors, using your model to replace the marines. This can have some undesired effects, try duplicating the ghost instead and replacing the model with yours and testing, thats assuming you did this.
This is all speculation i can think of 5 or 6 things of the top of my head that can be causing an issue, from the program you used to make the model, exporting options to galaxy editor side of things. I would test what i said first and let us know your findings, and double check your naming convention.
No detail is to small when asking for help.