Ok, since you think we need to logic better, I'm going to extrapolate from your claim regarding Horus having infinite power. If we are to take this statement literally, then it stands to reason we must do the same when reading other pieces of 40k media. Correct?
Thus, when a plasma reactor or fusion reactor detonates, and is described, as is common, as "a newborn sun", we should assume that in fact, a stellar body the size of our sun has formed in the middle of the battle, instantly killing the entire planet and forming a gravity well that throws the rest of the solar system into chaos.
When a Tyranid or Ork horde attacks, and is described in a novel or codex as "uncountable", or "endless", we must assume that in fact, the number of orks/tyranids is so large that mechanicus cogitators or Necron computers or what have you literally cannot count that high, in the first case, or that in the latter, that there are an infinite number of orks or tyranids in that battle.
When the impact of something strong is described as "like the fist of an angry god", you are saying whatever that is hits with equivalent force to a literal god, and we should assume that a punch from Khorne is equal to whatever mortal weapon or strong person that is.
Whenever one of the space marines gets angry and described as "their choler rose" or something similar, we should assume that in fact, the defunct medieval medical theory of the four humors is real science in the 40k universe.
When, in Betrayer, Magnus the red is described as looking like a pagan idol of burnished copper, we need to assume that he actually looks like some he's made out of copper
Whenever a custodes's armor is described simply as "gold", we should assume that it is in fact, made of the element with the atomic number 79, and is thus soft and malleable and provides poor protection.
When the Heresy is described as having "set the galaxy aflame", we should assume that in fact, the majority of the Milky Way galaxy, even the literal light years of empty void between star systems, was at that moment literally on fire, despite the physical impossibility of such a thing and the lack of fuel.
That Horus's power being described as infinite, that means we should assume he could delete the entire observable universe with a snap of his fingers, rewrite reality to retroactively make the emperor his slavishly loyal supporter from day 1, and the emperor could do nothing to stop him.
Do you see the issue here? This is the logical conclusion of your way of interpreting things.
