are they really? i don't see how unless its 2D,i wouldn't recommend adobe for any game designing especially not for 3d modeling, programs like maya, mudbox, zbrush, or basically anything made by autodesk would be best suited for gaming with 3D
Yes, game models are designed in Autodesk Maya, 3DSMax, or Zbrush but you must have sufficient knowledge of interface for the software you choose.
Models are 3D...concept arts are 2D...You can actually do "3D" in Illustrator, but I don' think you want to do that unless you really don't have any idea how to use 3D program, it' just looks like 3D, it is not going to be animated or change angle, it's just like painting~don't really know what you want but hope this helps a bit.