^What Sci said. Would it have really killed anyone to make the Suliban the Orions?
To be fair, they gave themselves an out with the Suliban because they lack a homeworld. Indeed, the Suliban Cabal seems to have been little more than a highly-advanced terrorist organization that was able to exert influence primarily due to the advanced technology granted to them by Future Guy.
They had an out with the Xindi as well because of the great distance between Earth and New Xindus. (I subscribe to the theory that most of the Delphic Expanse was located spinward of Earth and above -- thus explaining why most of the Federation's growth seems to have been in the opposite direction, antispinward, towards the Klingons and Romulans, and why the UFP didn't encounter Cardassia and Ferenginar much earlier in their history -- they were staying away from the spinward direction of the Alpha Quadrant because the Delphic Expanse had freaked them out!)
I'm thinking more along the lines of the Tandarans, who seemed like they'd be really important and then disappeared forever. And, really, there was no reason to bother creating the Xindi -- it would have been much more effective if it had been the
Suliban who attacked Earth in 2153 and if it had turned out that the Cabal had been amassing its weapons in the Delphic Expanse. But I digress.