my thoughts:

horseman of war: magneto

i think apocalypse teleported and didn’t just kill magneto (not just coping trust) and made him the horseman of war. hear me out, we all remember rogue’s speech to en sabah nur and that likely inspired him to go after people the xmen love. erik personally hurt him greatly and was his counselor in his war against rama-tut hence making him the horseman of war now a sort of twisted penance/karma for trying to manipulate and use him.

horseman of pestilence: cable (young version)

the reason cable had to go to the future as a baby was because of sickness (hey? hey? seeeee). i’m not very familiar with cable in the comics, so i’m going off the show but the prophecy says cable will stop him but not how, and marvel’s not afraid to get wibbly wobbley timey wimey. this is a stretch but it could be why apocalypse wants teen cable so badly (besides the obvious fact that he’s supposed to stop him) plus someone two team members love greatly and would hurt to see suffer? exactly who apocalypse is looking for. maybe that’s why the prophet lady (i’m sorry i forgot her name. i swear i know xmen lore) was so set that jean and scott must be absentee parents because that separation and pain is necessary to win.

horsethem of famine: morph

okay this one will be a stretch but bear with me. (again, remember rogue’s speech.) famine isn’t just literal hunger; it’s hunger in general. unrequited love could be compared to a hunger for what you can’t have and since you can’t have it… it’s constantly eating at you, making you constantly hungry. like rogue, morph is constantly going home to something that’s not waiting for them but for very different reasons. this last last episode almost cruelly honed in on morph and the unrequitedness of it all, so it seems like it could be purposeful to set up maybe possibly this twist. how would apocalypse know?? idk maybe he has a stellar gaydar like he did pick up on cherik after all. i mean if lady deathstrike can pick up on it so could apocalypse. plus, morph got a whole episode centered around them so it seems they’re going to be scarily essential…