One of the things that made Perfect Dark 64 great was the variation in AI personalities. As I recall, the sims I included most often were the JudgeSim, VengeSim, and KazeSim.
Anyone who played that game realizes how much fun those personalities added. Players could be given a similar mix of roles with supportive interfaces.
For example, a player in the role of Judge could be shown only the player with the most kills on radar. The same could be done for a Venge role. Another player's role might be to lay traps and explosives.
Such multiplayer might get complicated, but roles of this general style are worth considering.
Also, it's not always necessary for competitors to each have access to a type of knowledge (like radar). It can be alright for one player to have different information and tools than another player, as long as that's considered in the rest of design.