Warlord is only useful when you get the last blow so it's mostly any characters dealing a lot of damage and preferably doing damage with auto attacks.
Pawn would be more useful as mentioned with characters that are less about damages and more about support, CC, or range to have a clear line of sight for free.
Plus unless you can oneshot anyone on the first turn, Warlord won't be triggered at the beginning of a fight.
It's great for clean up though.
Balancing a game isn't all about the numbers.
