In Mordor, many mobs, even random landscape mobs, have more avoidance. If you copy your character to Bullroarer, you will see more complete blocks, parries, evades and resists, even by level 106 trash mobs. Partials will hit for less as well.
One reason is that the conversion from finesse rating to percentage has changed. The conventional wisdom was that 12000 finesse (3 t8 finesse essences) was enough, but that probably won't be true in Mordor. Here is the fraction that a mob's b/p/e and resistance is reduced for the finesse ratings on live and the current beta for update 21:
Finesse |
Landroval |
Bullroarer |
15188 |
26.5% |
14.6% |
27066 |
39.2% |
21.6% |
Quest and instance gear in Mordor includes significant amounts of finesse, suggesting the devs think we'll need it. There is no finesse essence in the North Ithilien or Ithilien-Infused Essence Boxes. You can get a Major in a Far Anorien Essence Box for 35 Host of the West Silver Pieces, and can upgrade it to Greater and Supreme with recipes for Long Lost Coins from the Featured Instance barterer.