Board Thread:Development/@comment-26393217-20170201131119/@comment-5395153-20171124190715

Lore-wise, both the Selentine Empire and Lysean Empire had Elephants according to Warlords 3 and the timeline respectively. This implies that Elephants not only reside on the Pasha Plains (a small area southwest of Elenia), but also the Stormlands and/or Colis Tarn (the Stormlands are the plains south of the Doomwood).

In TPC spiders were added to the Swarm more as friendly units rather than actual Swarm units. We don't want the Swarm to have duplicates though, rather a unit which blends the two factions. I've found no evidence of spiders siding with the Swarm (unfortunately the Realms of Famine didn't exist until Warlords Battlecry 2. Until WBC3, Melkor/Melchor was simply known as 'Famine'), the addition was only theoretical. They have however been seen siding with some other factions, possibly because they worship similar/friendly deities or have a similar goal.