Who said it is good. I think not.
The lord of Patni Bhava is staying at Labha Bhava; he will gain a lover.
Labha is thing we easily gain or expectedly get.
For spouse or an opposite sex, when we get it easily, unexpectedly, there was an old saying as a 2-foot-creature gain.
It could mean that the spouse or an opposite sex will gain something for you. But I never found this to be true.
There was only a 2-foot-creature (a lover). Most of us like this, especially for men. We thought it is good, but actually it will become suffering.
If there are a lot of women come after him, and he eventually get a partner, he might have to stay with her without love. He will not have the one he loves, but to stay with whom he does not. That would be a pain for the rest of his life.
If a Sun (1) is related to his ascendant, he will be a face-lover, fear of losing his face. He will pretend to be happy.
If a man getting a spouse with recklessness and also keep getting more and more women, he will enjoy them and be proud. But later on, he will suffer and have a lot of problems.
He will have a financial and family problem. He will not have peace.
For the one who has this kind of horoscope with also a good Moon (2). He has a good manner and will be charming. If his lord of wealth is also good, that would be confirmed that 2-foot-creatures would keep coming.
For 2-foot-creature gain, it is anciently believed that it is great gain, so he will not get any other lesser gains.
I have seen a lot of examples, and it is true. Other might think it is good, but I do not think so.
Good Rahu (8) in backward sextile Labha Bhava could be ruined by stocks.
Impaired planets are still beneficial.