Board Thread:Game Discussion/@comment-158.230.100.102-20130623175426/@comment-10842377-20130624093539

Not sure if that is the case, I think the difference the often overlooked 'Defense' rating of the boss. Last event I was going a lot more damage to a lvl 5 Wheeljack than I was to a level 5 Ratchet - which confused me until I noticed that Ratchet has a very high defense value.

In this event, Scourge also appears to have a higher defense value (relative to it's level in the boss tiers)

Also, in this event the bosses are leveled differently, a lvl 1 Scourge is around 9m HP, while a level 1 Ratchet was much less (if I recall correctly, a lvl 4 ratchet was 9.3m HP). This is probably down to the bosses having up to 7 'normal' levels this time.