Pirate race.

Not quite. They only had their fleet destroyed on the island, so they took their ships back. They remained as strong as they were.

Of course. They were so strong that what is Retribution to them, huh? While the world was crumbling, they were calmly getting drunk under the protection of powerful pirate mage-renegades? Although, I'm just nitpicking to prevent the emergence of a new race. Of course, after the armageddon, civilization collapsed, and many hunters, pirates, bandits, and others appeared. Basically, like in Fallout.

P.S.: But, if we are to provide any significant arguments. In my opinion, the pirate faction is the same as, for example, the faction of vagrants or peasant rebels. There is something to it, but, in my opinion, there are more suitable factions to introduce into the game.
In general, I am against it because, in Heroes, races and factions are usually synonyms. That is, each faction is a separate race with its own flavor, uniqueness, customs, and appearance. I would not introduce many human races. Daring pirates have a rather interesting atmosphere, but they are too secondary against the backdrop of the Castle due to their racial affiliation. When introducing pirates, the number of human units will become quite large and, at the same time, quite monotonous.
And also, most importantly, about half of the pirate units are included only to fill the gap in the level ladder. In general, try to convince me )

In general, I am still in favor of 1-3 neutral factions.

P.P.S.: There is an error in the title of the topic. It needs to be corrected.