I can think of two:
1) The Chaebol's youngest son
https://www.mangago.me/read-manga/the_chaebeol_s_youngest_son/
2) Medical Return
https://www.mangago.me/read-manga/medical_return/
omggg thankyou so much!
These each have a shrewd regressor mc
https://www.mangago.me/read-manga/this_is_the_law/
https://www.mangago.me/read-manga/acting_genius_top_idol/
https://www.mangago.me/read-manga/judge_lee_han_young/
https://www.mangago.me/read-manga/god_of_autopsy/ if you can't takd kihda drastic views then better leave this one out
https://www.mangago.me/read-manga/legend_reboot/
can someone recommend me something similar to “Real Man”? or just a really great mc being sent to the past, not really dungeon setting, more like real world setting. i like mcs that's really great in manipulating real world situations to his advantage like CEO Han. thankyou very much