Really? Personally I felt like Dark Souls focused more on your twitch reactions(and would probably fit your criticism much easier tbh). MH is more about just watching telegraphs for attacks and remembering how long your own attack animations last.
The only BS stuff happens with stuff like Tigrex where they have fast constant charging, but most of the monsters in the game have telegraphs that are replayed very often due to the long fights.
Zamtrios, for example, has a telegraph where he rears back with his tail in front, staring at you. If he just looks forward for more than a few seconds, he'll do a straight forward charge. If he turns to face you, he'll sprint directly at you. If you get too close to him while he's reared back, he'll tail spin. It's little details that matter, even small things like stomping their foot can tell you what they're going to do next.
I would like to hear a bit more elaboration though; do you have any examples? Just saying "split second decisions are impossible" isn't a lot of context.
I assume you're talking about how monsters move in general during combat.