Agree with others who have noted that the best uni for someone varies depending on a variety of factors, including course, budget, accommodation, location, and a number of other factors.
The rankings you have identified are quite different--with the first two being national rankings and the last two being global--and using them together in an attempt to derive composite ranking tiers really doesn't make sense in most cases because they measure different things. I think you need to pick and choose from the various criteria what is more meaningful to you and go with that. Some have suggested that they would favor the global rankings (QS and THE), and I can certainly see some reasons for doing that, depending on the candidate.
You note that you're an "international candidate," but you don't say from where, and you don't say for what level of study. If you happen to be from the US, you will be well familiar with the US News and World Reports (USNWR) rankings, which (for anyone who doesn't know) are the most used and quoted university rankings in the US. I would suggest to you that the USNWR rankings are more closely aligned with the UK national rankings than they are with the global rankings, at least insofar as undergraduate education is concerned.
Take for example, the QS global rankings and its ranking for Dartmouth, which is a member of the Ivy League, and widely (if not uniformly) regarded as an elite undergraduate institution in the US. QS ranks Dartmouth at #205 globally, behind 45 other US universities, while USNWR ranks it #12 nationally. Similarly, QS ranks Georgetown at #281 globally, behind 54 other US universities, while USNWR ranks it #22 nationally. Notably, QS ranks Georgetown lower than it does Arizona State University (#262), which USNWR ranks nationally at #121, nearly 100 spots lower nationally. The Times Higher Education rankings provide similar disconnects between the global and national rankings.
In addition, global rankings like QS and Times Higher Education don’t even include universities such as Williams, Swarthmore, and Amherst, which lead the national liberal arts category in the USNWR rankings. Students from such schools matriculate to the very top graduate programs in the country (e.g., Harvard, Yale, and the like), and anyone in the US knowledgeable about higher education would know that they are excellent universities filled with students of Ivy League academic caliber. Generally speaking, my impression is that the global rankings favor large universities with strong graduate programs and speak less to the academic caliber of students or rigor of teaching at the undergraduate level.
I think most people in the US would agree with me that they would consider the national rankings to be more meaningful than the global rankings, as they are generally more in line with the academic caliber of the student bodies attending the universities. Indeed, USNWR also has a global university ranking, and I’ve never seen anyone use that ranking as a barometer of how universities in the US are viewed domestically. Moreover, even Times Higher Education tacitly acknowledges that its global rankings do not provide a particularly good view of how universities are regarded within the United States, as evidenced by its separate national ranking of US universities, which is publishes in partnership with the Wall Street Journal. (See
https://www.timeshighereducation.com/rankings/united-states/2022).
Before I start a war, let me be clear that I'm not saying that one type of ranking (domestic v global) is "better" than the other, especially as it concerns the UK. My point is that rankings need to be understood in the context of what they measure, how they weight their various criteria, and with the understanding that different people/audiences value different things.
In the US, there is a very clear distinction made between undergraduate education and graduate education insofar as rankings are concerned, and the most relied-upon undergraduate ranking (USNWR) does not even consider research as part of its methodology. In the US, a common denominator for every single university considered elite is student selectivity (high test scores and high pre-university grades). For example, at the top 10 USNWR ranked universities, at least 75% of the entering class (that reported scores) have standardized test scores at the 96 percentile or above and exemplary grades, with the average admit being even higher--the student selectivity floor is very high. (While student selectivity officially counts for only 7% of the USNWR methodology, it is essentially baked into other heavily weighted factors such as "undergraduate academic reputation" and "graduation and retention rates." In the US, a university without high student selectivity will not carry a strong undergraduate reputation and will generally not have as strong graduation and retention rates.).
Global rankings such as QS and THE, on the other hand, do not consider the academic quality of a university's undergraduate intake at all. Instead, they focus in large part on research output. As such, to me, the global rankings are most meaningful for students in graduate programs who are conducting research, especially if they are considering working internationally. But I understand that my perspective is colored by my US upbringing, and the fact that, in the US, the starting assumption is that every elite university will have very high student selectivity--the closest analog in the UK would be A-levels, IB scores, etc. In contrast, it is my impression is that, in the UK, university reputations (for both the undergraduate and graduate level) are often tied to research output, which is why we hear so much about the Russell Group, though people seem to acknowledge that, although some Russell Group universities are highly prestigious, others are less so. (The closest analog to the Russell Group in the US is probably the Association of American Universities (AAU):
https://www.aau.edu/who-we-are/our-members. These are all great universities, and some of them are truly elite, but the listing is not in any way a marker of the universities that people in the US would regard as the most prestigious for undergraduate education. Most people in the US will have never heard of the AAU).
All of this is a long way of explaining (by way of an example) my view that, to the extent one is consulting rankings, one should try to understand them in the context of what they measure, how they weight their various criteria, and with the understanding that different people/audiences value different things. I have my personal biases--I care about quality of intake (because these are people with whom one will be interacting with daily), post-graduation outcomes (job and graduate school prospects), and educational environment (overall happiness and teaching quality)--but these factors may not matter most to you or the audiences about which you care the most. Best of luck.