Tactics for the Swamp (Fortress).

SWAMP

Many say that the swamp is a bad and useless faction in Heroes. Supposedly, the swamp-dwellers have no advantages over others. I disagree with this and want to convince such people that the swamp is a great castle.

- didn't convince me - listing unit features is not the same as superiority, and as for the two mentioned heroes, I won't even go there - their development is a nightmare - you might start with the swamp and run around for a couple of weeks clearing mines, but develop it fully? No thank you (well, there are a couple of magnificent spellcasters there indeed). You should play this castle either on small to mid-sized maps where a pure rush is possible, or develop quickly and capture secondary castles - considering the swamp seven as the main striking force in the second or third month of a decent map - I think that's unrealistic.

Added after 16 minutes
to be honest, I love this castle and enjoy playing it - but only if the opponent is clearly weaker than me or it's the computer (then you set it to one against seven and off you go)))
I'll list the only serious pros (my opinion)
+ 1st - the troops are splendidly divided into two or three target armies without losses in quality (gnolls+archers go out on the first day to clear the small fry - then you can add the basilisks to them and clear all more serious stationary troops - flies and buffed wyverns clear out archers quickly - and then bulls with hydras and basilisks depending on the situation - the tank core - breaking through the unbreakable) i.e., before it comes to a battle with the opponent, you can promptly work over your own territory and grab a couple of neighboring ones.
+ 2nd - bulls - in the fourth-fifth week they take Utopia splendidly, which no other castle can afford (except perhaps vampires with raising undead).
+ 3rd - all fighters except bulls can, with some luck, be built in 8 days
and that's all (only infernals have fewer advantages)

Added after 28 minutes
serious "Cons" - my opinion
1st - a single army does not form for me from them - in a large-scale wall-to-wall fight, the following happens - gnolls (mowed down in small territorial skirmishes, and even if not, they present no serious threat to anyone since they are slow and weak), archers are nothing - a stack of 300 is a slight threat only to the first level and only with a direct shot, the dragonflies' striking power is small - you need to bless them, i.e., lose a spell, and even dispel doesn't pay off such that only the attack of enemy archers and secondary strikers is stopped, Wyverns - they are inferior in such fights to everyone of the same level and their poison is nonsense; the only thing is they can be increased in number thanks to "trees", but they aren't found that often and it doesn't make up for their 70 HP - bulls, basilisks and hydras - these are very serious, but very slow; the opponent has plenty of options for cutting out the bulls and ignoring everything else - all such fights against sensible opponents are lost by me with a 100% result, and I don't think it's due to lack of skill. Only a serious, order-of-magnitude superior spellcaster can save it, or maybe someone developed fundamentally in the style of Crag Hack, but a specialized one.
2nd - territory - swamp - if you are unlucky - I have the impression that even "your own" troops barely move on it.
3rd - bulls - very expensive building, God grant that you build them by the end of the second week - I often fail, and they are very necessary; without them, the swamp army is ignored entirely.
4th - level 3 magic tower - reduces the possibility of swimming out of a bad start to zero; there is nothing tricky until the fourth level (again, not counting necromancers - there you can go wild)))
Conclusion: if the opponent is not a fool, you're toast (I probably forgot a lot now, but this is time-tested - if I remember more, I'll write it)
I'll note that the pros, except for the bulls, are only distinctive and in no way fundamentally surpass other races, and quite the opposite - and by a lot