Tom Buchanan and George Wilson are quite different kinds of people. This is true in terms of superficial aspects of their characters as well as in their personalities.
Tom is a rich man from a rich family. He cheats on his own wife with Wilson's wife (and with other women at other times) and seems to feel that he is entitled to such behavior by dint of his great wealth. Money, for Tom, serves as "moral insulation" and so as long as his wealth remains he does not feel bad about the bad things he does (like cheating on his wife, hitting Myrtle, holding racist views, deriding Gatsby and others, etc.).
George Wilson is a mild man and meek. He is of the lower classes and lacks imagination.
According to Nick, “he was a blonde, spiritless man, anemic, and faintly handsome.
Both men treat Myrtle as a type of possession (in keeping with the theme of wealth and possession that animates the novel) and both are apparently willing to disregard Myrtle's real feelings and desires.
Neither man is completely honest. (Wilson borrowed a suit to be married in and Myrtle was furious to find out about this fact later.)