Why `E^(-)` values for Mn, Ni and Zn are more negative than expected?

Why E^(0) values for Mn, Ni and Zn are more negative than expected ?

Why E^(Theta) values for Mn, Ni and Zn are more negative than expected ?

Why E^(@) value of Mn, Ni and Zn are more negative than expected ?

Why E^@ values for Mn and Ni are negative?

Why do Mn, Ni and Zn exhibit more negative E^(Theta) values than expected ?

Why standard reduction potential (E^(0)) of Zn^(2+)|Zn system is more negative than expected ?

Why is the E^(0) value for the Mn^(3+)|Mn^(2+) couple much more positive than that for Cr^(3+)|Cr^(2+) or Fe^(3+)|Fe^(2+) ? Explain.