All software developed for closed-hardware systems is completely dependent on the hardware used. When talking about consoles, the two are very closely linked, so I'm hardly changing my argument to discuss both.
I said that Football Manager, in its current state, is a complete hog, and not even the PSP version could simply be ported to the DS and work, hence the hardware would not be up to it. So to make a version for the DS would require an entirely new version of it to be written completely from scratch, and I doubt SI would bother wasting time writing that software. That's not changing my point, that's considering the full possiblities.
Anyway, this argument is going nowhere, and we're wasting needless posts bickering about semantics. I don't think we'll ever see an FM DS, and probably not any management games at all, unfortunately. You, on the other hand do.