Well, you can't get Howlrunner + 7 APs, you can only get Howl + 6 APs (she's +6 points over an Academy, and you've got 4 points to spare with 8 Academies).
Howl swarms will be focused more on formation flying with at least some of the ships. Full swarms of 8 TIEs basically don't care about their formation at all. If you're good at flying this, and can still bring all their guns to bear against key targets, that's awesome, but it's more difficult than a more tightly regimented, offensively powerful swarm with Howl's re-rolls.