[akhtene]

1) As you remember, the Watchers were subdued by light. Perhaps the orks knew that it was just impossible to overcome the Watchers by sheer force, and in whose hands could a light be? Elf's or tark's, of course.
2) 'Tark' for orks is a swear-word, isn't it. So can't 'tark's work' for orcs just mean hell of a job or devil's doing. Something hard and causing trouble. [img]smilies/evil.gif[/img]
Btw the Watchers are hardly Numenoreans' artefact. From the description of the statues - 'vulture faces' and 'claw-like hands' - it's hard to believe that disciples of elves could produce something that ugly.