Regarding whether to remove certain factions or not, my opinion is "no." It's perfectly possible to play 9 maps with different factions, in my opinion (personally, I can't imagine Heroes without any particular faction, especially since the tournament is based on the principles of chivalry and honor, and it's necessary to test the strength of each Castle).
Regarding navigation and other controversial skills, we can discuss it. Yes, navigation can be removed where there is no water. But again, in my opinion, I love maps made with the sea, and when they are well-made, I am very demanding (in my opinion) when it comes to maps. Therefore, among the maps presented in the tournament, there is likely to be one with a water environment. Unless, of course, the Knights decide to burn me at the stake for it.