[quote=@Skallagrim]
The armor isn't that strong. It spreads the kinetic force out. But it does not stop a concentrated attack. Since he likens it to kevlar a directed, focused attack will pretty much negate the armor.
[/quote]

^

Also it worth noting that there is a limit to what it can reduce trauma wise across a wide surface. Your basic war hammer would ignore any protection the great clock gives.