Why Mn atom show maximum valency of 4 with F atom?

Mn ($3d^5$, $4s^2$) can have maximum 7 unpaired electrons in excited state so it should have formed MnF7 molecule but it can form only MnF4 molecule.


Is it because:
$d\_{xy}, d\_{yz}, d\_{zx}$ orbitals are not axially oriented and therefore not suitable for head on sigma overlap but can form pi bonds as in Mn2O7 molecule.


