A correlation analysis explaining Target balances via components of the balance-of-payments is not very smart. Just as correlation is not causation one can also say causation does not imply correlation.
Since Target2 is by accounting identity the balance-of-payments with the rest of the Euro area one can directly calculate what share is due to the different components.

HWS often describes this by an analogy of a car with two different fuels between which can be switched. After you arrived at your destination you can of course say which fuel contributed for certain number of kilometers but on your way the fuel alternatives do not have to be correlated with the driven kilometers.