Both are about brothers
one as a "good" and the other "bad".
they both have nice plot twist
both Thai drama

The main idea that these two have in common is that the ml are yakuza or in Gokushufudo former yakuza.
Besides that I would say G is a lot. more comedic and good comfort show.

Its storyline is a bit messier
but the overall vibe is the same
ps: there is cheating so if that bothers you a lot I wouldn't watch it. since its not morally correct

+It has a similar vibe
+problematic characters
+In MG only the girl goes back in time
+ both are a duo

+It both has FL who time travel
+warning it has many problematic scenes and characters
+In MG the girl is preventing murders