I hate to break this to you, but you fucking fail at metal.
Considering that "Thunderstruck" came out in fucking 1990, as well as the fact that there are piles of songs from their early career that are not only much faster and more aggressive but also grittier and less bombastic (i.e. "Beating Around the Bush", "Let There Be Rock", "Kicked in the Teeth"), it's clear that they were not trying to replicate "Thunderstruck" all the time, and it's also clear that the rest of their songs aren't "weak" in comparison.
If you ask me, the whole arena rock schtick they fell into during the '80s was weaker than the tight hard rock they were doing before - except Back in Black is still one of the greatest arena rock albums ever.