Okay, so in my latest list, I included two swarm-bases, for the potential of poison close combat, with my other units. In different tacticas on this side and as a general tip, people seem to recommend that swarms should engage closecombat, after another unit has engaged firsthand. My question is: Since people recommend charging with swarms in the corner of an enemy unit (For fewer "attacks in return") and lining Swarmbases up 1 wide, will the second swarmbase get any supporting attack? - Or can swarms get supporting attacks at all?
Everything gets 1 supporting attack, unless they have a rule that gives them more (like monstrous infantry, monstrous beasts and monstrous cav do); or if they have a rule where they don't get to support (like the mounts from cavalry/monstrous cav). Short answer is the 2nd rank of the swarm gets 1 attack. -Matt
Swarms are Skirmishers though. I can't recall if that allows them supporting attacks, since Skirmishers never count as having ranks.
Lizardmatt is correct. Everything gets 1 supporting attack unless there is a rule specifically give them more. No such rule exists for swarms, so second-rank swarms get one attack each.
There is no need to worry about 1 vs 5 attacks for the supporting swarm. At WS3/T2, they will very quickly be stepping up and getting their full 5 poisoned attacks