Arcane spells are a whole different thing than trading a barbarian's rage for favored enemy and then taking Swift Hunter.
I'm going to stop you right there and let that sink in some, kthx.
From the looks of it, you're getting caught up about me saying to use a barbarian for this, which is understandable given that I posted in a scout/druid thread. I meant exactly what I said with barbarian because a barbarian can directly give up rage for favored enemy as per the
SRD. And even then it doesn't work by RAW because, while the barbarian can qualify for Swift Hunter because he does have favored enemy, the benefits portion specifically lists scout and ranger. I did not mean it would work for a druid using its own ACF to gain rage, then the barbarian's ACF to gain favored enemy, because chaining those ACFs is not really supported within the rules.
It is possible to argue that because the ACF says "as ranger" for favored enemy that the character should be treated as a ranger for all intents and purposes related to favored enemy, but since the rules don't explicitly say the character should be treated as such beyond that, nor is it implied strongly enough to pass strict scrutiny, the argument for the ACF won't really go anywhere and thus there's really no point in taking the feat even if the character technically qualifies. Personally, I'd say a DM should allow it because it's a rather minor change for some good flavor that won't break the game, but one's mileage may vary.
I simply meant there was a possibility a DM could allow barbarian with that ACF in place of ranger for that purpose, not that it fully worked by RAW. There was no need to insult me over it.