I've tried on google "xin" and found a page on wikipedia about a general from this period who conquered yan for Qin but failed miserably to conquest chu
So I wanted to discuss it here : do you think it's the model for our MC Xin?
so far the story keeps a certain historical logic (while many things are somehow changed or distorded)
you can see for yourself https://en.wikipedia.org/wiki/Warring_States_period the chronology is about good in the manga, the characters are (for many) not.
for example "wang jian" was one of the best general at the time and is to be portrayed as "wang Qi" in the manga so...he died early before most of his prowess in the battlefieldXD
I was checking some forums like the mangefox forum and many people were sure that the Li Xing from history was the model for xin
but : then wang qi should be alive and kicking
Li Xing was not from a low birth
and I don't think Xin will become a loser when a general in the manga (in history Li Xing had some great victories but he ended all with a huge defeat losing 200 000 soldiers against Chu, after that nobody knows what he did, surely he didn't do something worthy to stay in history)
so, getting back to the topic my opinion is since wang qi is dead and should be the avatar of history's wang jian, xin will do the job of wang jian as the successor of wang qi in the manga
so far in the story wang jian is nowhere to be found so wang qi was certainly "him"
I hope it will be like that, don't want a xin losing miserably whithout a chance to get back his honor