I spotted one single contradiction in the novelization:
"At the sound of footsteps, the soldiers leaned against the walls ~and each other~, ready to fight. But there was no fighting this enemy. The crew of the Monarch realized in a split second that they were ~defenseless~. (...) An army of ghosts attacked them."
Meanwhile, later:
"Gibbs and Scrum fought ~back to back~, successfully repelling the ghosts' attacks."
Compare the crew sizes.
The Sparrow's crew numbered a dozen or so, while the Monarch's certainly numbered well over 100.
The Monarch's crew—experienced and trained soldiers—were wiped out in seconds, while ordinary pirates were not defeated in minutes.
In both cases, the Mary's crew was very brutal, as we see in the film.
And in both cases—furious.
The only difference between the two battles was the location – the first was in the Triangle, which temporarily appeared in our world, while the second was outside the "Uncharted Waters" area, where the Triangle could appear.
Could the Triangle, or even just being in the "Uncharted Waters" area, affect the crew's power?
Possibly.
But after the Triangle's collapse, its function was taken over by the Silent Mary, which is why the Triangle anomaly follows it. As a result of the "friction" of the anomaly from another dimension against our world, a paranormal storm was created and follows the ship. And the source of its power was always Salazar.
So, both the Triangle and Salazar were with them.
So, can this "weakness" of the Silent Mary crew be explained other than by artificially extending the lives of the main characters?
It is possible, although it is not immediately obvious.
The captains' motivation and command system.
Psyche, faith, and their use.
The crew of the Monarch didn't believe in ghosts. And the atmosphere of the Triangle terrified them from the start.
And then they were attacked.
And they immediately realized they had no chance, that they were defenseless.
An army operates when there's faith in victory. When there isn't, it often disintegrates (or becomes less effective) almost instantly. When they realized it was impossible to fight, especially against such a ghostly enemy, they immediately broke down.
They had never encountered such savage, animalistic, chaotic aggression before. They had no procedure or plan for something like this because they considered it nonsense. And the captain did nothing to direct or calm them. They had no point of reference. And these were soldiers accustomed to discipline and orders. (The same logic can be seen with Beckett at the end of PotC 3.) Panic broke out, soldiers surrendered and tried to flee. In other words, there was almost no resistance to the ghosts. A few tried to defend themselves, but as the growing number of wraiths had nothing to do, having quickly exterminated the panicked majority, they attacked more and more people. Complete chaos erupted. The Navy doesn't want such powerful chaos, so they probably weren't even mentally prepared for such an eventuality. And Salazar's crew exploited that chaos. They had the psyche of a bloodthirsty pack. They attacked anything that moved. You see it in the movie. Since even such a large crew didn't defend themselves, they were wiped out almost instantly.
However, after the Black Pearl's surprise, Barbossa immediately directed the crew and set goals.
"Whatever happens, stay the course" – he understood the need to buy time. He calmed Carina and secured their arrival. He set a priority and an overarching goal.
"Defend yourselves! To the death!" (Or sth)
"This time we will not surrender the Pearl!"
– this is a POWERFUL motivation and a very clear goal. There was no turning back. He stabilized them. He was their reference point. He gave them a sense of purpose. That works more powerfully than hope. They didn't break down. He strengthened their courage. He removed panic – they weren't thinking about escape, but about defending the ship that had been their home for decades. They did everything they could to defend the Pearl and survive. And they did it together. Barbossa doesn't need an immediate victory. He just doesn't want panic, because he knows it will kill them (and that's what Salazar is counting on). Barbossa doesn't promise victory, but he gives them a reason to keep fighting, and more importantly, to fight as best as they can.
Besides, pirates generally thrive in chaos.
Their psychology is more flexible, more instinctive, and less dependent on rules. They are... accustomed to chaos.
This gives them a psychological advantage against supernatural threats.
Salazar often relied on chaos.
He knew his crew was a bloodthirsty ~pack~ of predators. He used them as weapons of mass destruction.
He "poured" them onto the battlefield like ants on a cake, and they slaughtered every living thing, even without a stated plan. Only chaos. This was often brutally effective, though not really strategical. And Salazar's presence on the battlefield further enhanced the crew's effectiveness and worsened the opponents' chances – on the one hand, a point of reference, on the other, pure fear.
The captain doesn't issue commands during the battle. The crew operates instinctively. They are brutal, but chaotic. The battlefield becomes a tool of aggression. Every opponent is bombarded with unpredictable brutality, truly difficult to control.
Barbossa minimized panic among the crew, set a clear goal, and gave meaning to even a very risky fight.
This is why the Pearl's crew was effective despite the sudden surprise, while the Monarch collapsed in a second in a similar situation.
It turns out that physical strength and numbers aren't the only deciding factors here – all three ships have formidable warriors.
What matters is how they exploit the people's psychology and the ability to manage chaos.
Toms couldn't prevent chaos or calm the people, Salazar exploited chaos, and Barbossa was able to prevent it and also inspire courage in the crew.
That's the whole difference.
