the problem with your argument its because you ignore everything else and just focus on one single thing
>the undeads were enemies of the horde
> the demons were enemie of the horde
>undeds join the horde
>OBVIOUSLY DEMONS CAN JOIN TOO, LOOK AT THE UNDEAD, IS CLEARLY AS WATER HERP DERP
you forget , no, you dishonesty ignore, a fucking ton of information, variables, lore and interactions and focus in one thing
"they were all evil and enemies, if one can be good and join the horde, the other can too!!1!, simple math!1!"
no, its not that simple, thats why your argument is meaningless and useless