I believe the author's idea in the last two maps was to have players use expendable units to distract the enemy, preventing them from attacking the Castle (capturing which means defeat) because it's virtually impossible to defeat the Dwarf. (Probably the only way is to have Berserk, Subdue, and Invisibility in all stacks from the Shadow League, and Sandro's Cloak).
jjoker is right about the last maps, as this was already discussed earlier. In general, I always create complex maps, which I then simplify at the request of players. I only play through my own maps (and only my own) on the Hero difficulty setting occasionally. I always play through maps on Veteran difficulty, and if they are passable, I publish them. (I consider myself not a very strong player, so I leave the "Hero" difficulty for strong players). But sometimes there are flaws in some maps, both in the AI and in other aspects, including author-created ones, and sometimes complex maps become easier because of this.
P.S. I have an idea for the next map, which will be even larger, and therefore have a more diverse tactical component. (Difficulty and constant loss of some control points should not be a cause for concern). P.P.S. By the way, I suggested a light version of this map, but... (see the topic). :)