Setting the records in the Romance of the Three Kingdoms (Zhao Yun):
Chance: Around 5 %
I'll delve a bit more into the history stuff with the first two paragraphs, being a armchair and amateur historian myself.
While I've been pessimistic about including real, historical characters in the past, Dynasty Warriors presents a weird case. On one hand Nintendo is no stranger to
Romance of the Three Kingdoms (14th century novel) - which DW is based on - and Romance is an extremely important Chinese novel, comparable to Shakespeare when it comes to influence and the Illiad / Odyssey in terms of set up (AFAIK without gods, but the comparision remains). If DW was based on
Records of the Three Kingdoms* (3rd century text, annontated during the 5th century by another author) - which Romance draws from amongst other stuff - there'd be many more issues. On the other hand, the Qing Dynasty (18th Century) historian Zhang Xuecheng called Romance "seven-parts fact and three-parts fiction." so even if Dynasty Warriors is a further fictionalization of ROTK those thorny questions remain. I'm invoking a long gone historian here because Romance is very much tied to Chinese history and folklore, to the point that what is based on real events and what's fictional was already talked and debated about back then.
That doesn't mean Zhao or his DW counterparts don't stand a real chance though - one can certainly make the argument that being a video game based on a novel means there's enough separation from the actual wars fought 1750-1800 years ago (The actual Three Kingdoms period was 220-280 AD, although the Han Dynasty's power began to break down around 190 AD).
Jomosensual
's argument is also valid here, that despite the fictionalizations Zhao's still based on a real person and could be excluded depending on the rule.
DW as a game series itself does have a slew of merits. It's one of the most famous example of a hack-and-slash franchise. Its influence doesn't limit itself to the Zelda nor the Fire Emblem Warriors spin-offs, but it's saying a lot when Nintendo are fully willing to commit big-time IPs to Koei for those spinoffs. Its combo system in general lends itself to a Smash fighter pretty well. . Also, this series is very well known and even has the teasing (in a loving way) nickname of "lawnmower game" in China, an area Nintendo's fully aiming to get into with the Switch release there next year.
The biggest problem Zhao or his fellow DW characters, such as Lu Bu, have is that they have aformentioned competition. Hayabusa is Koei's frontrunner, and DoA is not that far behind. If I were a betting man I'd put DW as an outlier for Koei's first Smash spot, but a very real chance should Koei get a second character or a chance in Smash 6.
Want: 50 %
Intrigued by the character and DW in general, hasn't had that much experience with the game. Not much else to say there really.
Nominations: Concept: Valve rep x5
Predictions: Kratos 4,1%
Also, before I end the post:
This is also kinda weird because it appears Zhao was also a former ruler of China under the Zhao Dynasty, which may or may not make him 4th party depending on the rule. Not sure what it would be for a situation like this. For the love of god I hope I'm not wrong about that because otherwise I just made myself look like a massive idiot.
If I may be a bit nitpicky:
AFAIK the real Zhao Yun (the Zhao Yun in ROTK and DW) was a general, not a ruler. He did serve Liu Bei for twenty years, and died in 229 - early on in the Three Kingdoms period. There's quite a bit recorded of his years as a general, but apparently the information about him is still limited. However, both Records' author and Liu Bei's son would honor Zhao Yun. So even if Romance is exaggerating, it's clear Romance (and Dynasty Warriors) is building on some real and major accomplishments.
While there are two kingdoms using the name Zhao, both of them existed long after Zhao Yun's life. Under another tumultous period - the Sixteen Kingdoms (the 300s, not long after the Three Kingdoms). The 200s-ca. 600 weren't exactly the most stable time in China.
*(Sidenote and further reading: I'll link to
this discussion on ancient texts if you wanna delve into Records of the Three Kingdoms,. Specifically the "Bias in ancient sources" and "Using Ancient Sources" sections. AskHistorians is the only subreddit I can actually recommend because of the quality and moderation. Keep in mind, again, that Romance is a work with at least significant fictional elements, and Romance influenced DW deeply. )