The idea was not to kill the communists. In Greece after teh end of the Civil War there were no mass executions. What followed was a repressive system where communists and their families were excluded from the economic and political life of the country- ie no government jobs, no full political rights, nor right to contest elected office etc. The only way out of this was for the alleged communist to sign a formal statement of renunciation.
Having in mind the slogan (not widely known among TCs for obvious reasons) "better Turk than Red" and the above it is obvious that the Junta would have welcomed double union. There was no intention to kill the TCs, or the GC communists, just to prevent what they saw as the communist danger in Cyprus. Control not extermination was the goal. IF that entailed ceding part of the island to Turkey, then it was acceptable. From the purely nationalist point of view three quarters, two thirds, half of Cyprus would still be a net territorial gain for the motherland and thus cancel out the charge of yielding national territory.
This is how the Junta thought. The local Cypriot Enosis fanatics knew nothing of this. They were in another planet.