The next sentence of "A hero has no good wife" is "Lai Han marries a flower branch", which means that good people often can't marry a beautiful wife, but those Lai Han who are used to rhetoric can marry a beautiful wife.
Although this proverb has no basis, it will still happen in real life. Heroes often refer to people who are ordinary-looking, honest, not beautiful, but kind to their wives. Lai Han refers to people who are good at rhetoric, glib, irresponsible and philandering.
On the surface, it feels like this:
Decent men can't get a good wife, and rogue men can often get beautiful women. This is just a superficial feeling. To really understand the meaning of this sentence, we have to find out what the protagonist Lai Han, a good wife and Hua Zhi mean.
Judging from the correspondence of Lai Han, a hero should refer to a person with good conduct; Judging from the correspondence between flowers, a good wife should refer to a beautiful wife. In this way, the meaning of this sentence should be: honest people often can't marry beautiful wives, and beautiful women are often taken away by thick-skinned men.