I once had my players create d20 Conan characters (using the very first edition) but the game never got further than that. Still, I had a chance to read the rules and see what kind of characters came up.
1st level characters were almost unplayable or so they seemed to me

Without any experience with d20 system games there were no way in hel* that I would have allowed them to create higher level characters.
As an opposed argument I wanted to test the MRQI character generation back then when it had just come out. It took me about half an hour (without gearing up) and when I took a look at the skill levels the character was immediately playable if not a Conan himself. But that was not what I was looking for, anyway.
It is not often when you can actually create a character that even after a lot of playing is even close to the main hero of the (licensed) setting. For example I have all 3 different Judge Dredd games and I would not even start to dream on being able to play a character that was so capable as an old stony face. Ditto for Elric, Aragorn, Slaine and Conan (in particular). That's one of the problematic parts in licensed settings.
I have to admit that once d20 system characters get past a certain level the game is getting much more heroic than RQ game (without magic). d20 Conan characters just can take huge amounts of punishment and still keep on going. Is this a good thing? I don't know. It is getting sort of ridiculous after certain level.
What comes to skill levels the talk was about
lower skill levels not low skill levels. So, even when those elite NPCs have comparatively high skill levels (at least when compared to other NPCs) the PCs will probably have even higher skill levels at the point they come across those as opponents (same as in d20 version).
For some reason I never got the picture of Conan just going against huge hordes of enemies, at least in the books. I could be wrong, though.
So, I am saying that Conan RPG would work very well using MRQII rules with some setting specific rules or without. I'm not dissing d20 Conan, the d20 just isn't my cup of tea even in the Conan form. FantasyCraft seems to be closest to what I can run of all the d20 systems I have seen.
I have not tried SW but at least it
seems to work in Solomon Kane RPG.