As I understand it, the idea behind the Tournaments is to hold the final battles with full armies... for over a month... hence the time limit and restrictions...
It would be better to suggest a more sensible implementation of this idea (if I understood it correctly)).
Regarding mentorship. It is not needed in itself, but as a means to train tricksters, collect daggers from elves, goblins from orcs, and accumulate magic in the Necropolis. It is quite difficult to hide all this from the opponent, and besides, let's not forget about the rule on fair play; if there is a ban, this rule will work :)