You should suppose this is considering that both brutes are equal... So its an accorate view.
I think the Whip is the best. Ridiculous counter probabilities, fast, long range, good damage, lots of hits...
Sai comes second. Very accurate, lots of hits, always disarms, slightly poor damage.
The knife is third... more damage than the sai but sometimes it gets blocked by the shield even at high levels.
Most of heavy weapons are not that good at high levels especially against hyperagiles.