Salaryman ga Isekai ni Ittara Shitennou ni Natta Hanashi - Vol. 3 Ch. 23 - Sword and Shield

[MangaDex]

 

[welcome2atlantis]

I dunno what Overseas Agent means but it sounds strong!

 

[radstylix]

Isn't this just the basic hammer & anvil tactic:

Anyway, now I need an isekai where a Total War players gets isekaid.