I thought the other players have already explained it adequate...
In the territories 40 units of your guild army will be randomly chosen. If you hold a territory the units are losing their strength over time. The reason for this is because of the balancing - else strong guilds will hold the territories forever.
Please feel free to ask if you have other questions
GYNDE wrote:I thought it was 30 randomly picked units...
That's exactly what Uiqua said but the system message when you send an army to conquer a territory says: "... has sent 30 of your fiercest warriors to conquer a new territory." So, are they randomly picked from the minimum of 40 or 30 of the fiercest warriors? Or because they were randomly picked should be considered as the fiercest, as in it would be an honor for them do fight and "die" for us?