Do I need to have 3 people from my guild in the group for it to count as a guild group (for the weekly guild challenges), or will 2 suffice (since 3/5 is all that's needed for a guild group for a dungeon)?
Actually jut started a scenario, the other two non guild members left almost immediately at start. I decided to "Solo" the scenario and surprisingly I received a Guild challenge. This makes me believe as long as all members who complete the scenario are in the guild, 1 of 1, 2 of 2, 3 of 3. then the guild will get the challenge complete achieve!
I had 3 guild members in a group and just ran one of the dungeons, didn't get credit towards the achievement. they were doing world quests while I was running the scenario. But even when all 3 of us were in the instance it did not register as a guild group.