Rare Garrison missions and Garrison level

[Vasilisa]

Greetings,

I was planning to update few alts and level their followers to get rare missions (675 ones) but somehow I didn't get them. What are exact requirements? I've got 3 followers with 675 ilvl and got Item Level Army Achievement (10 x 650 ilvl followers) and my alt ilvl is 676. Does it require Garrison lvl 3?

[Mixe]

Instant pop for 15 chars:

675 char ilvl
3x675 followers
10x650 followers

All of them had level 3 Garrisons so if you dont get missions thats probably why.