If the design that Travelers Tales came up with for the LEGO LotR video game is close to what an actual Balrog set might look like, then yes, I'd agree with the "larger yet unique pieces" idea.
The description he put where it includes Mordor Orcs and no Uruk-hai would tell me that it is the scene in FotR where Saruman is telling Gandalf to join him, just before they fight and Saruman sends Gandalf flying up to the top of the tower. I imagine the set could be part of Saruman's study set off the larger central room with the Palantir.
So it would still be Gandalf the Grey.
Story wise The Betrayal of Isengard it should be Gandalf the White shouldn't it?
The description he put where it includes Mordor Orcs and no Uruk-hai would tell me that it is the scene in FotR where Saruman is telling Gandalf to join him, just before they fight and Saruman sends Gandalf flying up to the top of the tower. I imagine the set could be part of Saruman's study set off the larger central room with the Palantir.
So it would still be Gandalf the Grey.