Then if they die with honor they go to that god's domain, otherwise Hel gets them.
I believe that is only the case if they are priests of that Southern/Eastern god. Regular blokes all go to the same generic plane - see the mountain where Roy is surrounded by Southern casualties (even if they do have different queues to access the mountain). Which, if anything, might make the other pantheons uninterested in trying to poach dwarves from the North - there is a substantial cost in clerics, and the payoff is blunted if you don't get their souls in your domain.
There is a world of imagination
Deep in the corners of your mind
Where reality is an intruder
And myth and legend thrive
Originally Posted by The Giant
But really, the important lesson here is this: Rather than making assumptions that don't fit with the text and then complaining about the text being wrong, why not just choose different assumptions that DO fit with the text?