FileForums - Are there any specific compression methods for Telltale games?

I was looking at one Telltale game, Back To The Future: The Game. It's that episodic game based off the movie. (And yes, I checked the Specific Games index before posting this, the game isn't listed there.)

From my handful of attempts at compression (it was more like 2 though) with the games files, I found that adding Xtool (xZlib) got me the best size I could get so far, but it was bigger compared to 2 other groups (I am just going to call them M and C in case this thread gets locked for "warez talk") who had a smaller size.

C: 898.19 MB
M: 878.85 MB

My size was like 968 MB or so (I deleted it a while ago) and I am confused to what I need to add to get a size somewhere like the filesizes above. Both of those two mentioned have 2 langauges, and mine just had English, with the other languages (Germans/French) in a different archive for optional install. I guess the main question of this post is do Telltale games have a specific method that works well considering most of their data is packed with .ttarch files? I think most of their games follow this structure. Is it also possible that C and M had rebuilt .ttarch files during install, or am I just missing some sort of tool here?