I fight lost wars, see light, fear sight
I open my mind, need flesh, fear mine
So it's possible to have:
I draw a card which spawns 2 on the corridor. I now have:
Each one of these x3 separate 'mini Swarms' will move independently, depending on the icon shown, and each side will then only finally Merge as a tidy up?
All the swarms will immediately Merge in position, after all the Genestealers have Attacked.
So you would then have:
Any new Genestealers that enter play due to card-play will immediately Merge together with any others that are on the same locations.
Finally each Swarm moves if the icon matches.