[The 1,000 Reader]

If I'm not mistaken, a main problem with Sauron's direction of his armies is that he spread them out too much and thus made it more difficult to effectively manage his attention on such forces. 45,000 troops? What about the strength of Mordor? Cirith Ungol to go with that? That was Sauron's main problem: he never tried to focus his attention and resources to take out a land. All he did was make many attacks of less focus and less strength at the same time. If he simply used both the strength of Minas Morgul and Mordor against Gondor, it would have surely fallen. Gondor would be overwhelmed and faced with many more attackers, meaning an easier siege. Once that was complete, Sauron could have focused all three of his armies together to sweep the north.

Though I believe Lothlorien to be too well-defended to take either way by the time of LOTR, If he used more than one army and flanked the land with his forces, he could stand a chance of taking it out. Once Lothlorien fell, he could have gone back to the eastern lands to recover (or, depending on the casulties,) pressed forward to swarm Mirkwood, which would likely suffer from tremendous loss of morale with the fall of Minas Tirith and Lothlorien. Afterwards, The Corsairs would guard Mordor and Minas Morgul from south-bound foes on land and from sea while the hosts of Dol Guldur, Minas Morgul and Mordor would regroup and then sweep down on Rivendell, possibly recruiting some goblins from the Misty Mountains.