I am using Claymore Cryptonight/XMR/Monero miner with latest Crimson drivers with no issues.
He recommends those drivers because that what is using in his dev machine. Even his Ubuntu is 12.xx. So far no issues using his miners ETH, ZCASH or XMR with latest Crimson drivers. I think all his miners are also updated to support RX cards for quite sometime now.
Btw, can you support his latest v9 ZCASH miner --- it is out of this world!
There is no claymore version fo linux sory. He is doing only for windows.
Anyway
Crimson drivers are in R OS (and supports up to R9 380 Amd cards)
But RX OS has amdgpu-pro drivers which supports RX400 series and it can be uncompatible with this old XMR miner.