Before this event all I ever seem to get out of it was iron units, so I am enjoying it while it lasts but with this luck I am sure my SC Premium Summons now will go bad.
I did that for my first play through of each level but looked up guides once I hit snags. (Most of my units are still low level so I needed guides to see what units I should level as I only started playing 2 months ago roughly).
Best of luck with you developing strategies.