So...if tomax.cohtitan.com, the legacy site, is to be trusted...Broadsword actually does not have increased crit chance on any of its attacks when switching to stalker. They're all 10% chance when solo as stated by the formula which gives it a native crit chance of 7% and a 3% for each team member with you being included making it 10%...
Martial Arts however does have indeed get the higher crit chance, but on anything stronger than a pet or minion it's the same crit chance as a scrapper's without having the 33% crit chance bonus effect from eagle's claw.
Again, if the data from this site is still accurate. But if it is the same values, that's...disappointing.
On a positive note, it tells you the exact chance of each attack to get a stack of Assassin's Focus which all but 2 of Broadsword's attack has a 100% chance. So any primary set attack with a 10 second cooldown will always get a stack of Focus.
1. Every skill starts with a 50% chance base at 0 seconds of cooldown and gains 5% per added second. Example: Soaring Dragon - 95% chance/9 sec CD, Sting of the Wasp - 75% chance/5 sec CD. L
2. Low cooldown powersets are worse if you focus on 3 stack Assassin's Strikes i.e. Savage, Kinetic, StJ. Martial Arts is great for using Assassin Strike because it has long cooldowns, but short animation times. This is relevant as every set has a different animation time for in-combat AS. (Broadsword and Katana's are slowwww)
Stalker Martial Arts