I have done the leg work and now you can make an informed decision:
First, the DS numbers are for a 100 trained sorcerer self-cast spells (no 140) with max dodge/cm, 20+ magical trains/level and 7x shield and runestaff. No brawling weapon.
STANCE OFFENSIVE:
shield/runestave
You swing a closed fist at xxxxxxxxxxxx!
AS: +368 vs DS: +516 with AvD: +17 + d100 roll: +90 = -41
A clean miss.
Roundtime: 3 sec.
runestave only
You swing a closed fist at xxxxxxxxxxxx!
AS: +368 vs DS: +556 with AvD: +17 + d100 roll: +88 = -83
A clean miss.
shield/brawling
You swing a closed fist at xxxxxxxxxxxx!
AS: +368 vs DS: +537 with AvD: +17 + d100 roll: +9 = -143
A clean miss.
STANCE GUARDED:
shield/runestaff
You swing a closed fist at xxxxxxxxxxxx!
AS: +368 vs DS: +607 with AvD: +17 + d100 roll: +44 = -178
A clean miss.
runestave
You swing a closed fist at xxxxxxxxxxxx!
AS: +368 vs DS: +742 with AvD: +17 + d100 roll: +23 = -334
A clean miss.
shield/brawling
You swing a closed fist at xxxxxxxxxxxx!
AS: +368 vs DS: +673 with AvD: +17 + d100 roll: +27 = -261
A clean miss.
BRAWLING/TWC
guarded +1 twc
You swing a closed fist at xxxxxxxxxxxx!
AS: +368 vs DS: +598 with AvD: +17 + d100 roll: +80 = -133
A clean miss.
guarded +95 twc
You swing a closed fist at xxxxxxxxxxxx!
AS: +368 vs DS: +700 with AvD: +17 + d100 roll: +86 = -263
A clean miss.
offensive +95 twc
You swing a closed fist at xxxxxxxxxxxx!
AS: +368 vs DS: +501 with AvD: +17 + d100 roll: +30 = -120
A clean miss.
NO NOTHING (disarmed)
guarded
You swing a closed fist at xxxxxxxxxxx!
AS: +368 vs DS: +515 with AvD: +17 + d100 roll: +81 = -83
A clean miss.
offensive
You swing a closed fist at xxxxxxxxxx!
AS: +368 vs DS: +452 with AvD: +17 + d100 roll: +39 = -62
A clean miss.
As you can see, post-capped runestaff DS is the highest. However, it should be noted I have 20+ trains of magical ranks/level. If I remember correctly, shield/brawling has a higher DS until you get between 12-15 magical ranks/level (it has been years and things may have changed). If one was to add a 7x brawling weapon to the mix, your DS would be over 700 in guarded.