a warphead has two wounds and EXACTLY the same chance of taking a wound which auto kills a warlock. [as for that matter do ALL pyschers without a 'get out of jail card']
orc psychers also auto-pass their powers due to mob rule - even if they suffer warps
and yes i agree the ork codex is sadly dated, most units are either badly balanced or over pointed or both, so - LOOTAZ in battlewaggons and ORC NOBZ on bikes... still a 'good' army... chuck in a cheap copta for objective stealing and maybe some cybork mega nobz... still lots of good stuff in there.