i dont mean hand picked literally, duh. its a chapter comprimised of many other chapters, like the deathwatch, and basically an loyalist elite force. it was made out of need for an extremely elite force designed to hunt down and exterminate other excursion forces and if need be assassinate a leader. however they prefer to die standing, so no drop pods. teleporting suits me. they are very much a cityfight chapter, hence the lack of drop pods. they have taken significant divergance.
see but dont be seen
heed the wisdom of the ancients
eye to eye
die standing.
so simply, they have lots of dreads and venerables, prefer fighting in cities and dont like drop podding.
kinda like a squad of the worlds leading special forces operatives to put it in todays terms