ERZ3 is pretty easy as Tails. What I do is: jump and hit his head before his first attack. I can get up to 3 hits from that. After the giant circular bullets, I hit him 3 times again, and by then, he should get rid of the middle platform. If I was lucky enough to still have the one ring, I simply fly to his head, hitting him, and when I land, I recollect the ring, and hit him again before I lose my invincible-ness. Repeat. Beat in less than 2 minutes.
ONTOPIC: I also had a problem when getting this emblem. I thought the path was the hard path, as I had not played this level with Knuckles at the time.