I guess 9N is out of consideration.
I like RN5 but i hate the MIUI and, less n no updates over time by xiaomi.
M1 pro has no gorilla glass and with 2.5D its hard to use tempered glass(it looks ugly). And i read it get updates till Android Q..
Can we trust Asus on getting future OTA updates? My frnd's moto has very less to no updates so far...
Asus is trying to get market shares & timely updates is a good way to make long-lasting good experience. They are already pricing their phones very competitively.
Since Asus has used vague terms for update promises, I think we can at least expect an Android P update for it, if not Q, which is good.
As you hate MIUI, Zenfone Max is the obvious choice. the 6GB model has a better rear camera than 3/4GB model, so its just a bit inferior to RN5 Pro. Moreover, Asus will be adding EIS with a future update.
Buy Redmi Note 5 (not Pro) screen protector or tempered glass for it. Apparently, all Zenfone glasses have either lesser width or length. My cousin owns a Zenfone Max. For the screen protector, buy from mi.com as you get 2x screen protectors for Rs 120.
Honor 9N makes sense only for those who want a compact phone. It is significantly smaller & lighter than the other two. EMUI isn't as bad you might think but if you hate MIUI, I doubt you will like EMUI. EMUI is far more optimized than Vivo & Oppo's shit UI.