The competition between modern medicine and traditional medicine is seen in both dramas. In korean drama male lead travels to modern era while Thong ek is opposite, female lead travels to ancient era.

In both, female leads are vampires
Male leads provoke FL's instincts with their sweet blood.
FL finds ML irresistible.

In Your honor, the gangster takes place of his twin brother who is the judge, in Switch a swindler takes place of his look-alike prosecutor.
In both dramas, both leads missed on their better future opportunities because of family issues.
Male leads are good human beings who lost their way in the world who did wrong to them.
In both dramas they fall for their colleague fellow judge and prosecutor.

Both have Kwon Sang woo as the lead except his role is reversed in both dramas. In
QoM he is detective where in TAD he is civilian who has interest in solving crimes and helps the detective. In QoM the civilian role is done by Choi Kang hee.

main character replaces her twin sister who has unavoidable issues to solve and female lead enters in obstacle-full life of her twin and faces them.

there is murder mystery to solve from the start in both dramas..
story goes from past to present and vice versa
strong need of female lead to succeed at various costs..
cheating spouse..
complicated relationships..

The plot revolves around murder mystery and motives behind it, the suspects are close group of friends, also struggle to survival is common though the scanario is different.
In both series, you can see the evil side of human when he tries to survive by abandoning their humanity and values.

The story of both dramas portrays real life story and characters which are imperfect and every person has his angle of story in their life.

The ability to see through the future by the female lead is the main similarity betwen both the dramas, while the male lead helps her to go through these situations.

In Manhole, male lead tries to change the past events by travelling through manhole, while in POD 2 female lead tries to change past events. in both series changing the past reflects in the present in more bad ways.

Both dramas have star-crossed lovers.. Past lovers reunited in the present..
I found the theme for both dramas similar. slow and steady..
Heart-gripping melodrama.. break ups and make ups due to parental issues..