I love this idea. It basically makes players into nodes so you don't get people standing around licking ice all day, and instead forcing them to actually pvp.

You could have the marked players be partially random and partially related to battle high, so that players with high BH are more likely to become prize targets of the enemy - suddenly you have to take that 100 BH tank and move them to the backline, weakening your attacking power sightly and potentially shifting the dynamics of battle.

I like the idea of having one player per team marked as a gold prize (maybe worth 200 points) and over the course of the game smaller markers worth less (50 points) spawn on more players. Similar to in the nadaam where we the game goes on fewer nodes spawn, except here more nodes spawn to encourage aggression.

You'd have to make it so that successfully protecting a marked player gives a good bit fewer points than killing that player, so that teams would not be able to camp at their base for an entire game after getting a single gold kill.