I believe philzone just meant one with a secondary typing that resists Fighting so together it would be neutral. Also Steel/Bug brings in Bug, which is weak to Cobalion's other STAB, making Rock neutral as well. So philzone meant something like Metagross or Bronzong.
Although, a Steel/Ghost would be an interesting prescence in the metagame. So close, Golurk!
That what I meant - neutral.
Bronzong, skarmory and forretress was what I was thinking. Hopefully gen 6 gives us the steel and ghost type.