Problem with main Q

[Lancian]

*SPOILERS*

I'm kinda stuck on this one, I'm supposed to kill three ice dragons on Iceland to finally make alliance with Dwarves and Vikings, but before I got this quest, I've already been to Iceland and killed all the ice dragons units (including the one in Deep Cave and their queen), only ice dragon I did not kill yet was the one with 60 black dragons (and more other dragon types). Quest log still shows me 0/3 ice dragon of Iceland killed.

So, the question is - do I need to kill the last one named Ice Dragon and the game will know I've killed the others before, or I am missing something ?

Thanks for the help