What is a Muster Point?
A Muster Point is one of the first buildings you can create in your City. It is the central location from which troops receive their marching orders, and is necessary to send and recall marches.
Upgrading your Muster Point will increase the number of marches you can issue at the same time and the troop capacity of each march.
When you build an Outpost, a level 1 Muster Point will already be present. In an Outpost, a Muster Point determines how many different units of troops you can host. A higher level Muster Point will let you hold more units of defending troops.