Well, a build which i used to use farm trolls with my sword is:
Str-13
Tact-13
Rest-Swords
A swrod with +7 vs physical damage
A shield with +30hp and +10vs blunt damage or -2 in stance or -5/20
Skills:
Glads defence
Deadly riposte
Riposte
Watch yourself
Dolyak signet
Bonnetis defence
Healing signet
Endure pain
I was able to use it to take on groups of 8 trolls, more sometimes, including both bosses and their groups.
The only problem is that there is a chance it may not work anymore, due to the armour cap thing, but hopefully that will not be permanent.
Good luck, hope it works for you