Editing ScariksGPC Siege

For the wave of sieges I'm going to use the rules in Estate as a base. 

That means you subtract Siege Equipment + Assault Gear from the Defense Value of the fortification. Defender SE and AG subtracts from attacker's amount though its generally less and it always costs money since they can;t forage for it outside while under siege. Plus you can't use rams defensively and catapults take up space so there will be some limit on them once they come more into common usage. 

When you Assault:
Every point of DV left over gives +5 to the defending commander's Siege skill. 
Outnumbering by 2:1 gives +5/-5, 3:1 +/-7, 4:1 +/-10. 5:1 +/-12 etc. 
Quality of the troops folds into the outnumbering bonus. a Footman counts as 1, armored men are 2. Knights and sergeants just count as armored men in a siege. Bandits are half, commoners are a quarter and so on.

To reduce the fortress by bombardment, undermining, arson, etc:
Assault gear doesn't matter at all for this purpose. 
Use attacker's SE - defender's and give a bonus to the side that has the greater numbers (+1 for 2:1, +2 for 3:1 and so on).
Then start with the DV of the line of defense being reduced divide by the number from above. Every that many days make an opposed Siege roll. 
If the attacker wins reduce the DV of that defense by 1.
Defender win is no result.
Attacker crit is 1d3 DV lost.
Defender crit is 1 DV repaired.
Attacker fumble allows an unopposed roll by Defender. Success repairs 1DV, crit repairs 1d3.
Defender fumble creates a breach. This allows an assault using either Siege or Battle as the attackers pour through the opening.

Against a wooden defense you also add fire. This brings Assault Gear back into it but only the free point for every 100 men counts. Add this to your number from above. If the defender's don't have adequate water or the weather isn;t normal then I'll add another modifier. 

So for the current situation at the Pinnacle
Attack SE: 5 (2 onagers, 3 rams)
Defender SE: 0
Attacker 2:1
Attacker 100 men.

That's a 7. 
Outer defense of the Pinnacle is 12. 
So they roll opposed Siege every 2 days with an extra roll every 7th day. 
4 rolls per week at 25 vs 10.
Week 1: Helifer wins vs fail, Helifer wins vs fail, Helifer wins vs fail, Helifer wins with a crit vs partial. Only 4 DV loss though.

At Llud's Hall you'd also have a 7 due to the numbers advantage vs the first bailey's DV6. 

I'm not sure how to do casualties for this part. They should certainly be less than an assault, and even lower if you decide not to use rams. My instinct is to use the Estate Assault rules and divide by ten. 
Attacker win vs defender fail in Estate is A10%/D25% so 1/2.5 in this lower damage event.
Win vs partial is normally A25%/D25% but the lack of a crit line bugs me so I'll say that is the same as above for 1/2.5.