Haven vs. Fortress (how to play against dwarves?!)

Orcs can effectively counter Gnomes (huge boost, rage, which many also consider to be an unfair advantage). If you adopt your approach (450 creatures of level 2), imagine the power of the "Rage of the Horde" spell. How many goblins do you think the Orcs will have?

Gnomes can be destroyed by the Light Elves, if you take the hero Wingael.

Gnomes can be destroyed by Mages, if all creatures have tier 3 miniatures (and they will, as we will play until there are 450 spear masters). The Mages will cast the Mage's Sign spell and place double stacks of mines and walls, and simply shoot down the Gnomes with miniatures that focus on initiative and luck.

Gnomes can be destroyed by Demons with the hero Nimue, if you are lucky with the Amulet of Mastery. On the battlefield, it is possible to have 6 squads of Cave Lords.

Gnomes are simply killed by Dark Elves with a relentless rush. This happens on any map, as the Dark Elves simply destroy neutral creatures very quickly. On the highest difficulty, their city development is not much different from the Veteran level; everything is very simple, but how are you going to find a huge number of crystals for the Gnomes? You might not be lucky with the mine.

In general, I don't see any imbalance with the Gnomes. Yes, it is a very strong race, but it can be countered.

I have already tested the retraining option many times. My friends don't let me play Humans on a large map. Rather, training monks into knights with Isabelle is an unfair advantage. I advise you to try it at least once before arguing, because I am 95% sure of the Humans' victory.