All castles in Heroes 3.

I'll try to approach the evaluation of castles in the game from a different angle. For me, the strength of a castle is determined not only by the basic strength of its units or the low cost of acquiring them, but also by its offensive potential. As you know, the best defense is offense. In many cases, you need to deprive the enemy, and the hero in particular, of the ability to move (they have a habit of running off the battlefield with all their artifacts at high levels... it's annoying...). I will evaluate the castles based on their ability to deliver the first blow, by moving across the entire map with masterful speed, enhanced by your hero at the very beginning.

Castle.
Halberdiers. ---
Archers. -++
Royal Griffins. -++
Crusaders. --+
Fanatics. -++
Champions. -++
Archangels. +++
In total, we get 1 creature capable of a quick attack without casting magic.
In total, we get 4 creatures capable of a quick attack.
In total, we get 1 creature that is not capable of a quick attack when casting a spell.
In total, we get 1 creature that is not capable of a quick attack when casting spells and even using the advantages of its native battlefield or light artifacts with a similar effect.

Rampart.
Centaur Captains. -++
War Gnomes. ---
Great Elves. -++
Silver Pegasi. +++
Dryad Soldiers. ---
War Unicorns. -++
Golden Dragons. +++
In total, we get 2 creatures capable of a quick attack without casting magic.
In total, we get 3 creatures capable of a quick attack.
In total, we get 0 creatures that are not capable of a quick attack when casting a spell.
In total, we get 2 creatures that are not capable of a quick attack when casting spells and even using the advantages of its native battlefield or light artifacts with a similar effect.

Tower.
Gremlin Masters. -++ (weak, but they can take down a squad of skeletons, for example)
Obsidian Gargoyles. -++
Steel Golems. ---
Archmages. -++
Djinn Masters. -++
Naga Queens. --+
Titans. -++
In total, we get 0 creatures capable of a quick attack without casting magic.
In total, we get 5 creatures capable of a quick attack.
In total, we get 1 creature that is not capable of a quick attack when casting a spell.
In total, we get 1 creature that is not capable of a quick attack when casting spells and even using the advantages of its native battlefield or light artifacts with a similar effect.

Stronghold.
Hobgoblins. --+
Raiders. -++
Orcish Leaders. -++
Ogre Mages. ---
Storm Birds. -++
Cyclops Kings. -++
Ancient Beasts. -++
In total, we get 0 creatures capable of a quick attack without casting magic.
In total, we get 5 creatures capable of a quick attack.
In total, we get 1 creature that is not capable of a quick attack when casting a spell.
In total, we get 1 creature that is not capable of a quick attack when casting spells and even using the advantages of its native battlefield or light artifacts with a similar effect.

Inferno.
Imps. --+
Magogs. -++
Cerberuses. -++
Horned Demons. --+
Hell Hounds. --+
Ifrit Sultans. +++
Archdevils. +++
In total, we get 2 creatures capable of a quick attack without casting magic.
In total, we get 2 creatures capable of a quick attack.
In total, we get 3 creatures that are not capable of a quick attack when casting a spell.
In total, we get 0 creatures that are not capable of a quick attack when casting spells and even using the advantages of its native battlefield or light artifacts with a similar effect.

Dungeon.
Hell Troglodytes. ---
Harpy Witches. -++
Hell Eyes. -++
Medusa Queens. -++
Minotaur Kings. -++
Scorpioids. -++
Black Dragons. +++
In total, we get 1 creature capable of a quick attack without casting magic.
In total, we get 5 creatures capable of a quick attack.
In total, we get 0 creatures that are not capable of a quick attack when casting a spell.
In total, we get 1 creature that is not capable of a quick attack when casting spells and even using the advantages of its native battlefield or light artifacts with a similar effect.

Fortress.
Gnoll Marauders. ---
Lizard Warriors. -++
Dragon Lizards. +++
Great Basilisks. --+
Mighty Gorgons. --+
Wyvern Monarchs. -++
Hydra of Chaos. --+
In total, we get 1 creature capable of a quick attack without casting magic.
In total, we get 2 creatures capable of a quick attack.
In total, we get 3 creatures that are not capable of a quick attack when casting a spell.
In total, we get 1 creature that is not capable of a quick attack when casting spells and even using the advantages of its native battlefield or light artifacts with a similar effect.

Necropolis.
Skeleton Warriors. ---
Zombies. ---
Ghosts. --+
Vampire Lords. -++
Powerful Liches. -++
Death Knights. -++
Ghost Dragons. +++
In total, we get 1 creature capable of a quick attack without casting magic.
In total, we get 3 creatures capable of a quick attack.
In total, we get 1 creature that is not capable of a quick attack when casting a spell.
In total, we get 2 creatures that are not capable of a quick attack when casting spells and even using the advantages of its native battlefield or light artifacts with a similar effect.

Conflux.
Fairies. -++
Storm Elementals. -++
Ice Elementals. -++
Energy Elementals. --+
Magma Elementals. --+
Magic Elementals. --- (a friendly haste spell will not have any effect)
Phoenixes. +++
In total, we get 1 creature capable of a quick attack without casting magic.
In total, we get 3 creatures capable of a quick attack.
In total, we get 2 creatures that are not capable of a quick attack when casting a spell.
In total, we get 1 creature that is not capable of a quick attack when casting spells and even using the advantages of its native battlefield or light artifacts with a similar effect.

Let's count the number of pluses and minuses. We come to some conclusion.

Faction/level 1 2 3 4 5 6 7 + -

Castle. --- -++ -++ -++ -++ -++ +++ 13 8
Rampart. -++ --- -++ +++ --- -++ +++ 12 9
Tower. -++ -++ --- -++ -++ --+ -++ 11 10
Stronghold. -++ -++ -++ --- -++ -++ -++ 12 9
Inferno. --+ -++ -++ --+ --+ +++ +++ 13 8
Dungeon. --- -++ -++ -++ -++ -++ +++ 13 8
Fortress. --- -++ +++ --+ --+ -++ --+ 10 11
Necropolis. --- --- --+ -++ -++ -++ +++ 10 11
Conflux. -++ -++ -++ --+ -++ --- +++ 12 9

We get the following ranking in terms of speed (according to my subjective method).
1) Castle, Inferno, Dungeon.
2) Rampart, Stronghold, Conflux.
3) Tower.
4) Fortress, Necropolis.
Therefore, the higher the position of the castle in the ranking, the more rapid its attack can be, and the greater the likelihood that with a good army, it will not allow the opponent to move. And, you know, I really thought about it and wrote it just now, and in the game, the situation is similar. I think that there is meaning in all of the above