My first try to calculate skellies stats with nearly the best possible gear, prebuffed skellies (AoKL + Homun) and all of the Auras (with Might from Merc, Conc from Pride, best possible Fanat from Faith) and battle orders at level 91:
First, the damage
225-base damage at that level of RS and SM
3.15-ED in skellies themselves
3.15-ED from Conc
1.44-ED from Fanat
3.10-ED from Mercs might
225*(1+3.15+3.15+1.44+3.10)=2664
Pretty good for a single skelly. Now the damage of a Full salve of them would be:
2664*15=39960
Now that's damage.
Attack rating:
1445*(1+1.10)=3034
Life on all difficulties with 80% BO:
Normal:
877*(1+0.80)=1578
Nightmare:
1089*(1+0.80)=1960
Hell:
1371*(1+0.80)=2467
Overall:
Damage: 2664
AR: 3034
Defense: 1445
Life: 1578
Life (NM): 1960
Life (Hell): 2467
Resist All: 70%.
15 Skellies Total.