Your units and army is coming along nicely, I really like it. A few notes and suggestions though:
Small (swarm special rule): Not need for this rule due to Warhammer's true line of sight rule.
Four Arms (Guardian special rule): I would just put these additional attacks into their stat profile, and just put their flurry of attacks nature into their background - few and simple rules are always better.
As for the guardians, I assume they are monstrous infantry? With their good offensive hitting power and 5+ scaly skin save, I would not give their any additional armour due to balance. other than that, great job
