Traditional, but excellent use of cyclops kin. For the other giants, that is some cool world building.
With sorcerer kings, I do agree that if they really wanted to wipe out the giants they could. However, remember that Andropinis and the whole city of Balic found them difficult to deal with. It may well be that the refusal to deal with them stems more from effort and risk than political need. AKA the cost in resources and making yourself vulnerable to other SK outweigh the possible benefits.