OK so my bleeding+pierce Brigand completed Legendary A5 and it worked well. It was not a self-found toon but after some analysis I think it could be done with self-found (unlike my burning damage Magician which is almost impossible). The main problem with self-found is that you will be forced to invest more str instead of dex since you are not garanteed to find all good gears to reduce str requirement. That will reduce your damage since you lose dex, but I don't think the impact will be large enough so that you can't play this build.
Under construction
The idea of this build are driven by a simple question: how to fully utilize the bleeding damage multipliers from both Hunting and Rogue mastery? The "normal" Brigand build, regardless of weapon type, focus mainly on (converted) pierce damage. Spear, bow, thrown weapon, if you take a close look at the dps numbers and do some calculation, you will find that regardless of the stats on your weapon, bleeding damage is actually a neglectable part. Or in other words, if you take all bleeding damage out, Brigand will still be Brigand, still high dps, nothing changes. This is due to two major problems.
1. DoT stack. I assume you already know that.
2. What's the purpose to have additional DoT if I can kill the monste within 3 seconds?