Oracle Database Client Installation 12c minimal install - Centos / Red Hat 7
So you want to perform a minimal install and instead of using the Instant Client which is below 100MB with minimal requirements, you chose the full client that may occupy over 1 GB space and requires additional packages to be installed, but you want to go against the documentation and have an irregular configuration, that is still way more than what you would have to do by using the Instant Client.

Just use the Instant Client and follow the installation instructions of that.