The Overlord wrote:
... the Jem'Hadar's bodies would die within days without ketracel-white
If a Jem'Hadar was assimilated, I think it wouldn't need ketracel-white, the Borg would just turn off that part of it's brain.
I don't think the founders can be assimilated, can't they turn to fire? Also, though the Borg can adapt to energy weapons, it might not be so simple to adapt to a kamikaze attack. They never adapted to Worf's blades.
The ability to pop out ships quickly would overwhelm the borg and the kamikaze attack would be the Dominions strength. The Jem'Hadar and the Vorta would kill themselves as soon as anyone of them gets assimilated, then the'll be re-cloned to kamikaze again. In the end, I think a lot of resources would be wasted on both sides in a long drawn out battle.
The Winner: Everyone else.