Fit for purpose you ask, well that is debatable but remember the government "stipulated" the AW189 for this contract to help keep Yeovil going, if I'm not mistaken.
not the first time that jobs at Yeovil have taken precedence over quality of procurement of UK helicopters.........ISTR they weren't actually built there, only assembled which was a bit of a con.
Strange that the 189 should have pitch instability problems where the 139 doesn't (don't know about 169) - different design of actuator perhaps?