Not contradictory. They are packages that contain the 32-bit stuff for installation on x86_64 system. i686 is 32-bit. This article may explain this better.
To do what you seem to be trying to do you need to start with a detailed explanation of that. You really need to read and follow this first.
OM does not have separate i686 repositories, rather there are 32-bit library packages in the x86_64 and other architectures we do offer. To make these 32-bit lib packages work with older games you may need to create what we call a symbolic link to them, this is easy to do if you know the name of the OM package and the name the game software expects to find.
I am not a gamer so my help with that aspect of this will be necessarily limited.