That was the thread. It was a brief discussion.
Basically, when you create an entry with the same name, it throws your additions on to the end of that list (as far as I’m aware). I used an example in that thread, but this is what my addition looks like now.
{
"type": "monstergroup",
"name": "GROUP_ZOMBIE",
"monsters" : [
{ "monster" : "mon_ravlady", "freq" : 10, "cost_multiplier" : 3 },
{ "monster" : "mon_zombie_fetus", "freq" : 10, "cost_multiplier" : 2 }
]
}This edits the monster group called GROUP_ZOMBIE and adds those two monsters to that list, as though I had added them directly to the core file. This worked as of about a month ago, though I haven’t fiddled with the mod since then. I don’t see why it wouldn’t still work.