Added information: Is it because the first time I clicked "Loot and Occupy" and then when it didn't work and load it back then is still not valid anymore?

You need to occupy or raze, not loot and occupy.

Erik-Ray の投稿を引用：

You need to occupy or raze, not loot and occupy.

I reload it back, not working both for occupy and raze.

Sooo apparently for the game: The goblin boss and the Greenskins are both considered as "Greenskin" faction given that I managed to get achievements with both. But the dancing ork boss isn't considered a greenskin!. I am not 100% sure but this the result I achieved after playing all 3 factions of orks. I leave it here if somebody will need it in future.

Also you need to use the base factions for most of the achievements. Use the Dwarf Faction instead of Clan Angrund, etc.

Erik-Ray の投稿を引用：

Also you need to use the base factions for most of the achievements. Use the Dwarf Faction instead of Clan Angrund, etc.

Yea, I agree. There are some rare cases which is not like this but is not worth to risk to spent so much time for nothing. For all future player who hunts achievements , take the wording in warhammer 1 as literal.