I don't think you can cut it closer than this. (Destiny)
Last night, Mig did his first Vault of Glass run in D2. He was 1283 light. Yeah... that's only 17 levels below the enemies... but remember, there were a bunch of new mechanics that didn't exist in D1.
We didn't really have trouble until Atheon. The ENRAGE timer kicked on, we had maybe 15% of his health left... we can do that, right?
Yeah, someone forgot to take off for Detain.
Astoundingly, Hypnotic was outside the bubble, and broke us out, with maybe a second to spare.
I have never, in either game, seen an Atheon kill come SO CLOSE to the end of acceptable time.
(You might need to download it to read the text on the screen.)