Board Thread:Warhammer 40k General Discussion/@comment-25618639-20150406151006/@comment-6078851-20150410150721

correct, yes, but the genestealer process takes considerable time - at least 2 or 3 generations until the 'genestolen' start to reproduce purebreed genestealers, as well as the time it takes for genestealers to aquire enough people to make their numbers secure. what i'm talking about though is, instead of sending ahead genestealers they were to send ahead a 'spore-bioform', and once the world has been 'spored' then in less than a day the world would be crawling with termagants, hormogaunts, genestealers, carnifexes etc.

obviously this does require a significant improvement of the spore reproduction method, but if anyone could make that improvement it would be tyranids. but to add to the previous theory - maybe orkoid life is not only unlike any other life in this galaxy, it might be unlike anything tyranids have ever encountered too, and maybe they're having trouble manipulating the orkoid genome.