Advanced armament haki makes use of the flowing concept, but it's not its equivalent, it describes the advanced usage of it. In those translations I've read Hyou said that Luffy needs to gather the haki from all around his body, which makes sense and means that an advanced user can gather a huge amount of additional haki to put it into either that barrier tech (lvl1) or the penetration tech (lvl2), which he then can either channel through a weapon or his/her fist.
Look at those barrier moves or that clash from Roger and WB. Those moves have like an absurd amount of more power behind them than hardened base moves, cause obviously a much higher amount of haki is used.
Therefore guys like Alabasta Zoro, Smoker and Raisin aren't automatically advanced CoA users, just because they can cover their weapon in haki, which should have been obvious in the first place.
People seem to struggle with that concept, just like they do with CoO.
Enma does it to the extreme, if not mastered, where it pulls out all of the user's haki at once and puts it into the slash, probably the reason why Oden was the only one who was able to cut Kaido. Thing is, it sliced through his skin, which means it's not the lvl2 penetration tech that was used. That Kaido cutter move could be the individual most powerful adv. CoA lvl1 supported cutting attack tho, which would make sense, cause normally characters probably can't use such amounts of haki, where they are losing or nearly using consciousness, assuming that was Oden's ultimate attack and he let Enma go all out.