Uninvited guests.

New Rupert won't last long on this map; it puts the player at a disadvantage. No need to consult an oracle; just think about it for a moment. Horses appear in the Human Castle towards the end of the second week, so GG will have to deal with the first wave of attackers without any bonus. There are always significantly more besiegers than there are troops in the castle, and only an adventurer would dare engage in hand-to-hand combat – horses still aren’t helpful. Given the constantly deteriorating state of the castle and capital, finding money to train horse units is extremely problematic. Therefore, even by the end of the game, Rupert won't have a large, capable unit to confront the main opponents. And neutral creatures can be dispersed by any hero, especially since there's no fear of losing him and suffering a defeat.
Astrid also won't improve her situation by losing the ability to create Phantom Titans. I haven't seen many posts in the thread about her previous carefree life.
Urkrass's ability to cast random antimagic on one unit won't provide any advantages. Precisely because it affects only one unit, and that unit is chosen randomly. The Barbarians have very important combat units as well as mere cannon fodder. The AI casts spells on those stacks that are dangerous, and if antimagic doesn't work on them (which is likely), there's no point in bothering with this new hero. I definitely prefer to take Haggeesh rather than this scarecrow, because the bonus for her is significant and reliable.
Some dubious innovations.