I think these two dramas are similar because they both depict a character who is simply following his ideas and living his life, but he meets someone from the Communist Party and is unknowingly involved.
In War of Faith, the importance of the Communist Party appears later than in Shooting Stars, and both dramas are not just about Communism; War of Faith is also about the economy, while Shooting Stars is about police work and justice.

In both dramas, there is a body swap between a policewoman and a criminal. I would say Room No.9 is darker than Tengoku to Jigoku: Psychona Futari, which is more humorous at times, but still pretty intense and dark.

The main idea of both dramas is that the main character literally swaps faces with someone else. In LRRFTF, the main character's family tried to kill her, and she swaps faces with someone to get revenge and find out the truth about what happened. In NF, the main character didn't choose to get a new face, someone forced him to. He is also trying to discover the truth about the past event. In both dramas, the protagonists search for the truth and investigate while pretending to be the person whose face they have.
In fact, apart from that, these dramas are very different, but they do have some points in common.

These are both bl drama from Thailand with fantastic elements. In both, the male leads are fated to each other like soulmates and there is a link between past selves and present time.
IFYLITA has more mystery and is more interesting to me while UWMA has more romance.

In both, two skilled male leads associate with each other. One is severly injured and there supposedly is not any way to save him. In both, one male lead is very knowledgeable about martial art sects and matters ( Li Lianhua et Zhou Zishu). Also, there is a treasure everyone wants to get.
In WOH, the ultimate rival of the male lead is the other male lead but in MLC, the ultimate rival is the third male lead ( Di Feisheng).
MLC is about several cases connected to each other because one male lead is a detective whereas we can't say that there are cases in WOH even if the male leads investigate about some things.

I think both features really good friends who considered each other as family ( or "soulmates" in WOH from the words of the male leads ).

In both, the FL et ML have grown together and considere each other as siblings until the romance appears. The ML is the first to understand that he loves his "sister".
The ML has a complicated family situation in both, but it is more complicated in FIT.
In both the ML is really good at studies when the FL is not and needs his help.
The ML is seen as really handsome by everyone and the FL has many rivals.

I think that FIT is better thanks to its better story and quality but EF is not a really bad drama either.

In both dramas, the male lead gained the ability to see ghosts after having been on the verge of death. This ability will change their work and also their way to see life. Moreover, they use their ability to help the ghosts they can see.
TF is a drama about crimes and reveal the truth behind some deaths, while GD is a medical drama.

In these two dramas, a member from police needs the help from a student ( so someone who is not a detective and is supposedly not qualified to participate in an investigation, but he is ). The male lead is really smart in KSNJ5 and can do things that others can't ( mainly in ONHCT). But although they are good at investigating, they are not really smart in studies so others often look down on them.
In both dramas, they do not investigate common cases, mainly in ONHCT because it is a fantastic drama with supernatural elements. Both dramas can be both funny and really serious.
I would say that ONHCT is more serious because it deals with the theme of mourning througout all the drama. Neverthless, it still is a really funny drama even more than KSNJ5 in my opinion.