Your question, though flawed, is good. There are, however, several hermeneutical principles being violated in your question. Allow me to summarize one of them:
WARTS AND ALL
The Bible is nothing if not totally transparent regarding the failings and faults of the people whose names and narratives are found within its pages. The Bible does not gloss over their mistakes, their sins, their lack of good judgment, and the rough edges of their temperaments and personalities.
When interpreting the Bible, to expect perfection of even its heroes of the faith is unwise. To be human, even a regenerated human, is to be something less than perfect.
I've always balked at the expression "I'm only human" for a couple reasons. One, people often mouth that platitude to excuse or justify their faults and failings. Two, the expression may have the ring of truth, but it does not contain the whole truth, for to be human is a tremendous privilege and honor. To say "I'm only human" is by implication to derogate our being made in God's image.
THE IMAGE OF GOD
The psalmist said,
When I consider Your heavens, the work of Your fingers,
The moon and the stars, which You have ordained;
What is man that You take thought of him, [think here "How privileged is man that You take thought of him"]
And the son of man that You care for him?
Yet You have made him a little lower than God,
And You crown him with glory and majesty!
You make him to rule over the works of Your hands;
You have put all things under his feet,
All sheep and oxen,
And also the beasts of the field,
The birds of the heavens and the fish of the sea,
Whatever passes through the paths of the seas (8:3-8 NASB, my bolding and my gloss).
When reading this psalm, some Bible interpreters have the mistaken impression that the words "What is man . . .?" are an expression of the smallness and insignificance of the human species in contrast to the vastness of the universe, with its billions of stars--if not galaxies of stars! That is poor hermeneutics.
To be human is to have an inherent worth which exceeds that of the animal kingdom and the inanimate aspects of God's creation, whether a billion stars or a billion pounds of gold. God has invested a great deal in us and has proved his love for us by sending his Son to die for us.
THE PERIL OF INTERPRETING SCRIPTURES SIDE BY SIDE
All this to say, when interpreting the Scriptures, we need to keep in equipoise both the inherent worth of our humanness on the one hand and our inherent tendency to fall short of the glory of God on the other.
Therefore, when putting our Lord's words in Matthew Chapter 5 and Paul's words in 2 Timothy 4 side by side, a keen interpreter keeps in mind the dichotomy which exists between the ideal, as expressed by Jesus to love our enemies and pray for our persecutors, and the often less than ideal way in which the ideal is implemented by sinners saved by grace. Those sinners, by the way, include the apostle Paul!
Am I saying that Paul was sinning by invoking those strong words of denunciation regarding Alexander the coppersmith and those of his ilk? No, not necessarily. I am simply pointing out that Paul, as with all believers, had some rough edges to his personality and temperament which the Lord
was in the process of smoothing.Some of that smoothing, I imagine, took place in Arabia, where Paul spent three years subsequent to his conversion (Galatians 1:19).
As Johnny Cash said in one of his songs,
I'm just an old chunk of coal
But I'm gonna be a diamond some day
I'm gonna grow and glow
'Til I'm so blue pure perfect
I'm gonna put a smile on everybody's face
But I'm gonna kneel and pray everyday
Lest I should become vain along the way
I'm just an old chunk of coal, now Lord
But I'm gonna be a diamond some day
I'm gonna learn the right way to talk
I'm gonna search and find a better way to walk
I'm gonna spit and polish my old rough-edged self
'Til I get rid of every single flaw
I'm gonna be the world's best friend
I'm gonna go around shaking everybody's hand
I'm gonna be the cotton-pickin' Rage of the Age
Yes I'm gonna be a diamond some day ("Old Chunk Of Coal" Lyrics | MetroLyrics)
Yes, Paul was a chunk of coal. For proof, we need look no further than the sharp disagreement with the phlegmatic and easygoing "son of comfort," Barnabus (Acts 15:39). Furthermore, Paul told the Galatians he wished the Judaizers would emasculate themselves (5:12); he got into the apostle Peter's face for being two-faced and hypocritical (Galatians 2:11); and he himself admitted that he was the worst of sinners (1 Timothy 1:15).
In short, "even the gods have feet of clay," and Paul and scores of other heroes of the faith were useful, however fallible they were, in God's kingdom. They, as with all of us, were works under construction. As the children's chorus puts it,
He's still working on me
To make me what I ought to be
It took Him just a week
To make the moon and stars
The sun and the earth
And Jupiter and Mars.
How loving and patient He must be,
He's still working on me.
One of my favorite books is Orville E. Daniel's "A Harmony of the Four Gospels NIV" (Grand Rapids: Baker Book House, 1986). In it Mr. Daniel puts the texts of all four Gospels, not just the Synoptics, side by side in four columns, so that you can either follow the bold print from column to column if you want a continuous flow of text which includes all the information which is unique to each writer, or you can read the text of each writer separately, one column at a time.
That book is a perfectly legitimate use of textual analysis by examining different texts side by side.
The same cannot be said of putting two different genres of text side by side, pointing out an apparent contradiction, and then speculating as to how to account for that contradiction. That, however, is what you are doing in your question, and as I have suggested earlier, that is not good hermeneutics.