[rutslegolas]

I agree with Tuor of Gondolin,the men of Minas Tirth were in greater danger than they even could have forseen,and they certainly would have been destroyed had not the Rohirrim come to their aid at that time .

I should say that Denethor's policy did not work,I think he Should'nt have sent men to Osgiliath as a small garrsion . These men were slaughtered for no reason.
I think these men would have been better used if they had remianed in Minas Tirith.

And as Rimbaud says abondoning your strong defenses to a "raze an burn" policy is rarely succesfull.They could have used this policy had Minas Tirith fallen.