Correct me if I am wrong but Deathstrikes damage after the Pub is going to be checked by hiding and stealth. Half damage for bow users.

This would imply that you dont want ninja after the pub. Currently my brother runs with tact/poison AIer. He has no problem. With DS people can just stop and cure your poison making you waist tons of mana. Why not have tactics/anat? 35 damage AI max...that is only 10-20 damage loss in comparison to DS (if they run), but it is garanteed. You also get higher damage hits on average. With a low resist (most mages) you can very easily concencrate weapon and hit for over 20 damage per regular swing with 120 tactics/anat.

Ninjitsu is good if you get dismounted. Also, right now DS damage is very good. Planning for the future is good so go with ninja till they change it then swap it with tactics if the nerf is severe.

Hope this helps