This, and everything you wrote in your previous post is what I hate more about my actual game! I can easily add your snippet to my SM, but could I ask you how to change the faction of those undead not-so-undead? I hate Lich killing every other actor by the time I reach them, I have some limited knoweledge of the CS, but never played around with factions...
Would it be rude to ask you to explain it to me via PM, or send me your modded version of FCOM?
Not rude at all, but probably easier to post it here and that way others can do it too. It's quite simple really, but TBH, I can't remember all those that I changed, so you may have to do them as you notice them - Lichs were the biggest problem (Deep Lich, Lich Lord, Lich King, Nether Lich)
I used http://www.tesnexus.com/downloads/file.php?id=11536.
1. Open it up and load up all the automatically selected and active ESPs
2. Find the offending critter (ex. FCOM_Convergence.esp/Creature/Deep Lich)
3. At that point you should see all the ESPs the creature comes from - in my setup it's only Mart's Monster Mod.esm, and FCOM_Convergence.esp.
4. Scroll down the right hand pane until you see the faction section, and you'll see MMM adds the UndeadFaction to the object, but FCOM doesn't.
5. Right-Click the column where FCOM and the header "Factions" (on the left) meet, click add.
6. Click the blank spot that appears under FCOM, and you should see a drop down box appear.
7. Scroll down to - and select - UndeadFaction.
8. Repeat for any creatures you want to add the faction to.
9. Close TES4Edit and save it when prompted (back-up should be created automatically).
If you've never used TES4Edit before it can be a little daunting at first, but once you've used it once or twice and understand it, it'll get easier.
Edit: 10. Rebuilding your bashed patch is probably also needed.