Board Thread:Warhammer 40k General Discussion/@comment-8257990-20130821144250/@comment-8881468-20130825002532

depends

there is the starless void in between the galaxies, which, if the warp was like a tablecloth, overlapping with the materium, would mean that you would have "islands" of sentient life amongst the emptyness, more or less confining the entities of the warp to those islands.

we could also take other theories considering the nids into account.

1. we do not now how sentient life in other galaxies would develop, does it have to be carbon based?

2. nids would adapt to the foodsources given to them to specificcally battle those foes, they would maybe look differently if more of their enemies relied on certain standardised forms of battle (biologiocal or chemical weapons instead of energy and kinetic weapons)

3. given the nature of the long voidtravel in between galaxies, it might have been a strategy to make the fleets as energy conserving as possible, leaving out information and genetic basis for specialised units developed against opponents from other galaxies, trusting in the abilities of the hive to adapt to situations (see yrmgarl genestealers or fenrisian krankens or the sea snakes on the iron snakes homeworld)

4. Nids are mass based attackers who outlast their opponents, it matters little on what technological level an opponent is, they are able to reach "critical mass" to be nigh unstoppable nearly on their own (if given enough time). though we simply don't have enough backround info on that