Let me summarize the early Torchwood eps:
1) Revivification, death, alien monster, blood, incidental orgy with one-off characters, death, revivification, New Girl and Jack make eyes at each other.
2) Alien incursion, the alien has sex with every man in sight and kills most of them, fails to kill New Girl while seducing her by accident, alien is trapped by Torchwood and Jack brings someone back from the dead by kissing her.

They kind of went with that pattern. Sex, death, life, sex.

MIBs as such are kinda American, in style more than setting, which might be thought to clash with the uber-British Doctor Who vibes (another style-over-location thing). Jack himself uses up the entire possible quotient of transatlantic cooperation. However, it would be immensely amusing to have Torchwood, between orgies, run up against an MI7 where the black suits wear bowlers instead of sunglasses. I, too, wonder why this isn't tried (between orgies) in fanfic.