The SGP aims at a countercyclical fiscal policy, but is not designed to sufficiently support monetary policy in a lower bound environment in which monetary and fiscal policies can become strategic complements rather than substitutes. 4/6  BIS - Central bankers' speeches  And finally there are structural policies.
It is not only country specific shocks which present an issue, but also common shocks with diverging effects due to the structural heterogeneity within the eurozone. Going forward it will be crucial that the EU works towards structural convergence, which will limit the divergent amplification and transmission of common shocks across the eurozone.