I agree with all of this. Each of these men failed greatly and were great men of God. But I would like to stress the fact that Jesus has not yet been crucified when these failings took place. I'm not saying we don't sin now. But things are not exactly the same. We have access to the Holy Spirit now, which came at Pentecost.
Psalms 139:7
Where can I go from Your Spirit?
Or where can I flee from Your presence?
1 Samuel 16:12-13
So he sent and brought him in. Now he was ruddy, with bright eyes, and good-looking. And the Lord said, “Arise, anoint him; for this is the one!” Then Samuel took the horn of oil and anointed him in the midst of his brothers; and the Spirit of the Lord came upon David from that day forward. So Samuel arose and went to Ramah.
The above concerns David.
If I am wrong then open to correction.
If I got it right maybe others could add something for the other greats in the OT