I've wondered about that as well; whether or not they've stuck a few Iraq-war themes in there. In DJY too.
And that business about Sejong encouraging interracial marriage, I couldn't help but wonder if anybody back then would have wanted to support such a thing. Or if it wouldn't have started riots in the streets.
There is a Japanese Drama starting next year early called TENRIJIN about this mid ranking young warrior named Naoe Kanetsugu who was famous for his skill with the spear ,he started off with the Uesgi fought his first battle at 16 (4Th Kawanakajima )and ended up in the Imjin war .Right off the bat we will get Iraq comparisons and its hard not to given Hideyoshi's blundering . But what it will demonstrate is that most of the Daimyo Lords were not really into this oversea's conquest . We pretty much know the main reason for the Imjin War was that Hideyoshi was just too nervous having all these warlords with time on their hands so he sent them oversea's where they ended up misjudging Joseon and were bogged down until 1598 . The point is aside from fanatics like Kato Kiyomasa and Fukashima Masanori most of the warlords had their lands and familys held hostage . one of the leading Daimyo Date Masamune who participated in the second invasion (sort of )dressed his army in fake gold and himself in white (Japanese funeral colors )while having his retainers carry a huge cross behind him in anticipation of Hideyoshi ordering his execution (Ken Watanabe made his name in the 1987 drama Masamune The One Eyed Dragon ). Tenrijin is the first time the Korean Govnt has decided to let NHK film in Korea so the Japanese can depict their side of the Imjin war (and they wont pull punches they will show their own atrocities too although the main depiction will be how many Samurai Familys were blackmailed into participating . Its an interesting concept and will provide a nice counterpoint to IMYSS and KINGS WOMAN . Back to Sejong would he have promoted a slave to high rank ? not at all ,it would have caused a much bigger uproar than depicted and it would not have died down either . we also have Kim Hyo Bin given a makeover when in reality(from what little i know ) she was a Joseon Anne Boleyn only smarter as she kept her head . The whole Tsushima incident First no Minamoto were in Kyushu the Kyushu Samurai Familys were in order of power SHIMAZU (SATSUMA ) OTOMO OUCHI RYUZOJI The Minamoto went down by in fighting in 1219 ,though cadet branches like Ashikaga ,Matsudaira (later Tokugawa ),Takeda and Hosokawa would be around for a few 100 years yet . So Yoshitomo ..at the time while all the feudal magnates were embarking on 150 years of civil strife ending with the rise of Nobunaga than Hideyoshi ,Yoshitomo was cleaning up on the trade end of things with the competition busy killing each other off as such these Pairate Raids were as much a pain to him as to Joseon ,what Yoshitomo was guilty off was fence sitting and not reigning the Pirates in ,after a couple of minor show of strength raids by Joseon and faced with a loss of revenue that bothered Yoshitomo more than anything he clamped down on the Pirates and sent about 200 to Joseon for punishment .
The First 30 episodes dealt with various attempts to put the Wang Family back on the throne anyway interestingly i have found nothing in the Eng Language on this subject ,so my guess would be its a fiction which makes sense the Wang Family save for Wang Kun the founder were the pits ,we have almost 400 years of plots ,counter plots ,coups ,failed coups ,rebellions ,murder ,conquest by the Mongols ,meanwhile the populace endured famine ,illness ,poverty ,so why would anybody want the Wangs back ,it would be like having another 8 years of Bush only 20 times worse .
Another point ,in many K Dramas we see warriors with Japanese Swords ,the regular Katana plus the Doto (extra long )and the Wakizashi (short )well turns out that was the So Familys main source of income selling weapons to the Joseonese Government .