As most light novels out there this one has it's pros and cons
From a narrative point of view, the author describes things and sets the foundations to events making it a very coherent and consequential story, this brings some pacing issues at times and it can also be redundant with the explanations and Ryouma's monologues (a problem too common in web novels unfortunately). It's also quite mature, for example, slavery is taken very seriously and brutally depicted. War is likewise way more deep than most novels I've read and I'm not qualified to judge on how accurate it is but the strategies, action and counter-action and conditions of each battle are both well explained and executed. It also doesn't go (so far) on the harem route, the two females are also mature and don't frown on him nor impose themselves on him, not to mention that for a change it makes sense that they would want to throw their luck and bet on him for their future (for those who come from the manga, the girls here are not pushy nor needy nor interfere in Ryouma's life when he for example goes to a pub and sleeps with the waitress). Which brings to the next point, Ryouma treats women as women, he's not the classic idiotic virgin that gets a nose bleed when a girl talks to him and has 10 beauties asking him to have sex with him and he is either oblivious or too shy about it, Ryouma for a change he has relations with some women and in an adult fashion.
Yet for all the attention to detail, is at times inconsistent, for example, summons are random and from earth as a hole yet each and every summoned person is Japanese, if the author was going to do that then was it not better to just restrict the summons to Japan? That would also solve the language issue, otherwise all earthlings just speak and more importantly read the isekai language which needless to say, can not be the same as all languages on earth. Also some characters act are presented in one way but later in the story act completely out of character, I won't get into it to avoid spoilers. Same goes for the story, the author seems to be loosing interest or steam as he progresses and the logic and consistency ain't as sound after volume 4. And as the guy below, Jandalman says, the output of the author is slow, very slow, there is with luck one chapter per month and I'm not talking about the translation but the official JP release.
As for the story, there ain't much to tell, MC goes to an isekai, he's been trained by his grampa to kill or be killed so when he's about to be made a slave he strikes preemptively and kills the summoners. There is a leap of faith that need to be made to accept this at face value but all fantasy stories demand such leap, that the author made it at the start and is thus a defining quality of the character makes it an easy one to accept for me, others will disagree. MC then tries to forge his life in this world and without spoiling much, he gets a purpose after finding the treatment his fellow summoned (Earthlings?) suffer and gets a fiefdom. Simple but well presented.
Overall, I like this one quite a bit if you haven't noticed, it's a good story, presented in a solid and consistent way (which I value highly), with real characters and a believable world. The bad, imo, is the pace and the aforementioned lose of steam on the part of the author which introduced some inconsistencies and "not so mature" aspects later on. I'm waiting for volume 6 to end to read it in one go, I hope it gets on track in it but it might as well get worse.
I have read up the the 10th volume officially translated to and published in English. I have very much enjoyed the story that Record of Wortenia War has had up to this point.
The Story has its flaws but the overall content, when boiled down to its essence, is very enjoyable. It has a lot of more real subjects that are taken seriously like "racism," slavery and war. It does have a few tropes about those subjects like "slave falls in love with their master" though. The story tackles those subjects pretty respectfully so I think it's fine. The story of the main protagonist is full of really good twists and turns and there is a lot of influence from historical tacticians and strategists in how they solve their political and war based issues. I think it has a lot of good points at the heart of the plot and I keep reading despite the issues it has because it's still interesting at the end of the day.
Having said all that, it suffers a lot of repetition and tangents in the narration of its story telling. On more than one occasion, I have heard the same ideas or thoughts expressed in identical and reworded ways up to 3 times within the same page or two of each other. These flaws feel like obvious filler material in the grand scheme of the story. There are meaningless tangents about non-essential story components or about side characters that you will never see again. Even the peasant farmers that have no significance can have pages of description with no justification for going that deep. In the 10 Volumes I have read, there has been about as much story progression as what I have experienced in 5 or less from other popular authors. That is by no means a knock on the quality of the core story but the franchise feels less valuable when I buy a $7.99 to $9.99 volume and each chapter in some volumes can easily be summarized in 2-5 sentences. I have skipped entire pages of filler before out of pure frustration that a single conversation is taking up the whole chapter and not had any problems skipping around to get to the point.
To move on and start wrapping up, the illustrations are pretty good when put up for comparison with other franchises but I'm generally not big on its style. Some of the illustrations also are just weird as far as natural human looks but that might be because of some of the odd angles that must have been difficult to draw. It's not the best out there but it's way better than I could come up with. I think it's just not my style. Characters in general are pretty well thought out and I feel like the author does a pretty good job with them and the relationship they have with one another.
In conclusion, I'll probably still keep reading this novel but it's flaws I mentioned would make my rate it 3 or maybe 3.5 stars instead of 4/5 stars. Pretty good but expect less for more.