in one turn, the knights of Isabel, led by Axel, destroy 2 squads of dwarves (any, but it's better to leave lava dragons for last).

This is if they are lucky enough to outrun the bears – more often than not, the opposite happens: the bears go first and scare the knights (they also lose initiative); even if they don't manage to scare them, at least the cavalry is blocked, and a tournament rush won't work. In addition, having trained cavalry (let's say, an additional 40-60 units) means the absence of inquisitors or adepts. Of course, their absence is somewhat compensated for by the presence of a super-squad of cavalry, but if the latter are somehow removed from the game, the consequences may not be very favorable. Therefore, a guaranteed elimination of any 2 dwarven squads doesn't seem guaranteed to me at all.