Comparative evidence

h₃erg

• Hitt. hark- 'get lost', 'disappear', 'perish' (EDHIL: 306f.)

• Hitt. harganu- 'ruin', 'destroy' (EDHIL: 306f.)

• Hitt. harnink- 'ruin', 'destroy' (EDHIL: 306f.)                   The connection of hark- 'perish' with OIr. org(a)id 'smite' and Arm. harkanem 'smite', 'smash' is unlikely, see Shatskov 2015: 990f.

References

EDHIL = Kloekhorst, A. 2008. Etymological Dictionary of the Hittite Inherited Lexicon. Brill.
Shatskov 2015 = Shatskov, A. 2015. Another verbal suffix in Hittite? Indo-European Linguistics and Classical Philology 19. P. 987–995.