Android Mobile - Forward Shading ? Flicking some actors

im getting flicking in forward rendering on some objects in viewport but they are only ones that were unwrapped with 3dsmax. i turn it off the problem goes away. do i need this will i lose performance without forward shading. why is this happening thanks

Make sure you dont have a mesh in your mesh (everything in the mesh is duped, causing z fighting), strangely common issue.