Actually the non-elect sheep don't come to true knowledge because they're, well, not elect, correct? Do you think that the wolves (see "Finney, Chuck") truly have a hand in their destruction? The non-elect sheep weren't/aren't led astray, they were born astray and always meant to be astray, correct?
It is not my right or responsibility to know the ultimate ends of God's final plan for redemption, is it? In fact, isn't that exactly what faith is, trusting in a future glory despite whatever present circumstances mitigate against a future hope?
(See Heb. 11)
With the OT saints I believe that whatever vessels fitted for destruction, and the circumstances that arise from their actions, will ultimately prove to be to the glory of God.
God's love and mercy is proven by His faithfulness to His word, and despite what we may think is the correct plan of action, the Father often employs counter-intuitive measures to fulfill His plan. (i.e. the foolishness of the cross)