Master non-common weapon like spear

Master h2h.

Use the non-common weapon in one hand, and dual parry weapon in second.

Try to pick a good moment (victim is resting up to heal etc..) and strangle, if you fail you can push on or vanish and try again later.

If you strangled and they have pets, feel free to push the pets out of the room, and perhaps strangle them too if you have time

Use your blind dust, but hold off with poison, don't panic, strangle lasts couple ticks or more usually.

When you are ready, use your poison dust, the moment it hits "murder" and disarm. The person will flee right away 90% of the time, leaving their weapon behind.

Follow on them, using murder and trying to get those caltrops in there to eat up their moves.

Remember to envenom your shrunken (ninjas have envenom I think and throw them. At this point all that matters is that you output more damage then your prey. With them blinded and poisoned and further poisoned by shrunken, you really should have no trouble especially with dual parry weapon..

Ninjas has a pretty rich combat choice, from grapple, to caltrops to weakening through that nerve skill.. If you can get strangle off you should have enough advantage to take on most people head on especially if they are hurt. They also have enough of weapon choice to really allow you to match your weapon. If you use a spear and dagger against a paladin for example, assuming you have dual parry dagger you will basically be in little to no disadvantage defense wise.