Snakemen spawn super early if you play on Jack Sparrow.
in oct 2601 on that mode, never aae them. neither in j.xx branch.
And hey, in sept i had a base attack by the dark ones, but still had not enconter them, aside a small failed tentatuve on the hhot pursuit mission. That was th 4th attempt, before had academy and ratmen! But may bask attack from doom enemies made more rare? ( it spawned s 50+ expedition wich im always not able to take out with 10 gals and warrior armors musjets and shotguns, other 7/8 are wounded yeah im quite adventouros!) Since they are devilish foes, they are not supposed to have "intelligence", may be made into someone else (humanists using them) puppets? I'sse these only on ground mission/random encounter (such as doomed faem mission) othervise i'll have to edit my .sav file before the raid takes place changing diff levelbto beat such attack, i've done and actually it worked!!
edit: are the zombies sopposed to csrry only UAC weapons? i. vase ceackdowns ive seen some with more standard weapons (heavy shotguns) and even some unarned