Aside from partying, which is what I think is most likely, what am I missing?
With that character build the two things that you are missing the most is needing a higher level and some more point into Skeleton Mastery.
The skeletons that you create are made with mlvl=clvl. Against diablo that means that their chance to hit is an attacker level of 29 vs. a defender level of 40. Very poor chance to hit and diablo will block 50% the hits that do land. A few extra levels should increase their to-hit percentage a lot.
With RS=24 and SM=3 the skeletal warriors that you make have a life of 517 (lying character screen will display the wrong life). And have an AR=410 and DR=410 with a damage of 81-83. By just upping the SM to 6 this will change the stats to life=793 (+53% gain), AR and DR to 455 (only modest gain but it helps) and the damage they do to 96-98 (about an 18% increase).
edit: P.S. I used a fire rogue when I did it.
The worst advice that I keep seeing given out is for necros that are using lots of skeletons is to max RS to the point of ignoring the SM skill level. The SM skill has a major impact on the performance of the skeletons and can frequently be worth sacrificing having an extra warrior so that an extra 3 or points can be put into the SM so that the warriors are sturdier and and do more damage.
I did diablo at about that level in a 2 player game with only a RS~18 and with their life at around 900 to 1000 each. This let them tank the BigD adequately with the help of the clay golem and Decrepify technique; plus a few mana pots so I could keep throwing up the CG constantly.
With that character build the two things that you are missing the most is needing a higher level and some more point into Skeleton Mastery.
The skeletons that you create are made with mlvl=clvl. Against diablo that means that their chance to hit is an attacker level of 29 vs. a defender level of 40. Very poor chance to hit and diablo will block 50% the hits that do land. A few extra levels should increase their to-hit percentage a lot.
With RS=24 and SM=3 the skeletal warriors that you make have a life of 517 (lying character screen will display the wrong life). And have an AR=410 and DR=410 with a damage of 81-83. By just upping the SM to 6 this will change the stats to life=793 (+53% gain), AR and DR to 455 (only modest gain but it helps) and the damage they do to 96-98 (about an 18% increase).
edit: P.S. I used a fire rogue when I did it.
The worst advice that I keep seeing given out is for necros that are using lots of skeletons is to max RS to the point of ignoring the SM skill level. The SM skill has a major impact on the performance of the skeletons and can frequently be worth sacrificing having an extra warrior so that an extra 3 or points can be put into the SM so that the warriors are sturdier and and do more damage.
I did diablo at about that level in a 2 player game with only a RS~18 and with their life at around 900 to 1000 each. This let them tank the BigD adequately with the help of the clay golem and Decrepify technique; plus a few mana pots so I could keep throwing up the CG constantly.