Sinestro was once a prominent member of the Green Lantern Corps, until it was discovered that he ruled his native planet Korugar-One mercilessly. Stripped of his costume and power, he was exiled to the Anti-Matter Universe... to reappear later as an agent of that universe's Weaponers of Qward, the counterparts to Earth-One's Guardians of Oa.
Wielding a power ring that absorbed the green plasma from the Lantern rings and converting it into yellow energy, Sinestro quickly became the deadliest adversary of Earth's Green Lantern, Hal Jordan. These two would have a long running enmity which would culminate across several universes of existence
He had a long and storied history of conflicts wherein at one point, Sinestro as an energy form (a punishment that the Guardians inflicted upon him for his continued disobedience) traveled to Earth-Two after assuming the form of cab named Goitrude. The cab was once owned by Doiby Dickles, the plan of that world's resident Green Lantern. Alan Scott. Once regaining his natural form, Sinestro recruited three cons from Earth-One and brought them to Earth-Two, wherein he transformed and multiplied them into a Sinestro Corps to control that universe. Both Alan and Earth-One's Hal Jordan aka Green Lantern defeated the assemblage of evil! These three crooks took the place on Earth-Two of three men influential in the life of Alan Scott: the second Red Tornado aka John Smith, and two of his foes in Captain Challenge and Vandal Save. All three migrated to Earth-One shortly after the three gangsters left for Earth-Two.
These gangsters turned clones labeled themselves the "Evil Green Lanterns", but were a short lived group, at least with fully functional power rings. When the two true Green Lanterns brought the Central Power Battery back to Oa where Sinestro had stolen it, along with their progenitor, this left the Earth-Two Sinestro duplicates leaderless. Presumably they each had similar egos and perhaps even some of his tactical aptitude. Nevertheless, these new creations would not have assimilated well on Alan's world. These clones were the cosmic twins on Earth-Two of Solomon Grundy's newer clones spawned during a plight in that world's Metropolis that Superman destroyed.
Well, since all other planets besides Oa had a parallel in both universes, the logical place to deposit these countless clones would be on Korugar-Two, where similar red skinned people resided with biology comparable to their counterparts. Without the means to quench their inherited thirst for conquest, these Sinestros may have accepted their new lot in life and reformed or persisted in their lawless ways. Still, this sole encounter by this crew of cronies against the Green Lanterns parallel Hal Jordan's multiple duels both solo and alongside fellow Corps men against the first fiend of Korugar!