Case 2) Two main slots are main-slot-only:
Harder to calculate. We have 3 subcases:
a) Headgear+Shoes: 12 options for the main-slot-only abilities (mso) (3x4)
b) Clothes+Shoes: 15 options for mso (3x5)
c) Headgear+Clothes: 20 options for mso (4x5)
Harder to calculate. We have 3 subcases:
a) Headgear+Shoes: 12 options for the main-slot-only abilities (mso) (3x4)
b) Clothes+Shoes: 15 options for mso (3x5)
c) Headgear+Clothes: 20 options for mso (4x5)
Comments
3 subcases again:
a) Headgear: 4 options
b) Clothes: 5 options
c) Shoes: 3 options
The last two slots we calculate similar to the 9 sub slots, we do (2 + 14 - 1) choose (14 - 1) which is 105 options.
Add up combinations for main slots (4+5+3=12)x(105)=1260 options
No subcases. We calculate similar to 9 sub slots, we do (3 + 14 - 1) choose (14 - 1) which is 560.
We add all the subcases (60+658+1260+560)=2538 options
We multiply by the options for the 9 sub slots
2538x497420=1,262,451,960
voila