Both are quite gloomy Chinese stories about the Fl's fate, her taking part in the palace power struggle and her foresight

Both are romantic stories about a female writer in her own fictional world. Palace: Devious Women has more connection with the real world and some unexpected twists in it

Both dramas are the stories about the FL trapped into the world of her own scenery but in Palace: Devious Women it has quite unexpected twist at the ending

Both are based on the same classic Chinese literature plot. Three Kingdoms is a long-long story, Growling Tiger is about the way of Syma Yi and his family.

Both are a low-budget romantic dramas where the action takes places mostly in the royal harem. Both have nice chemistry between the leads, a little bit of political scheming, some same plot twists and some typical Chinese melodrama clichees

Both have the same lead actress. Both are not free from clichés but quite quick-paced stories with lots of plotting and unexpected twists

Both are dramatic stories of the beautiful princess who is seeking revenge for her family in the world of betrayals

So, LR is fantasy and Ruyi is realistic (bcs the prophetic dreams plot was cut away from it) but they have smth in common. Both are fluffy and beautiful stories with good young actors about the toxic romance where one gives while the other takes.

I mean the FL is stupid (particularly in LR though her idiotism is well explained) and believes anyone except for the man who always helps her (but in Ruyi she is at least nice and beautiful). The ML is very pleasant to watch but he also is not smart bcs he cares too much about her.

Both are beautifully shot costume romantic dramas with beautiful actors. Both have marriage life and typical Chinese palace power struggle.
But the stories differs much, while Ming Lan is quite smart and restrained, the FL of Ru yi is not; Story of Ming Lan is more realistic, Ruyi Pavilion (aka Snowfall of wishes) is just sweet and fluffy.

Both are crime solving thrillers with no explicit romance or action -- where the lead is an extremely intelligent detective, where the characters live in the world of injustice but still believe in people.

Both shows are very quick-paced stories about power struggle.
Both have the same Chinese setting: a young scholar arrives to the capital, two princes are trying to get him to their side, each fighting for power. There are also a vile emperor who had came to power by force many years ago with the help of his friends; the local special service and its insidious head, one of those very friends; empress-grandmother, keeper of family secrets; emperor's sister with an illegitimate child...
All these characters have complicated relationship in both shows . But the MLs differ absolutely. JoL is not so serious as NiF, it is full of humour and the ML of JoL is not supersmart. (Moreover, he is sometimes saved by others. )
In JoL we also still don't know what girl the ML is going to prefer so we are waiting for the 2ns season.

Both are romantisezed biopics of ancient China's famous royal family women where the female leads are modernized and whitewashed but not transformed into superhuman Mary Sues. Also both dramas are not dragged like some other Chinese ones.