The Battlemonks use an M-10 Daggrafist fighting vehicle to secure the perimeter of a combat base. The use a common base for infantry type models is optional, but can make moving them easier. A typical "team sized" unit contains 3-5 models, there is no advantage in having 5 models instead of 3, it is simply a matter of how many models you want to sculp and or cast.
Billions of years have passed since humanity left earth and moved about the universe. In that time countless wars have been fought. Mankind has spread to every corner of the universe. Spacecraft have flown to stars using space fold, FTL drives, bussard ramjets, wormholes and every other conceivable means of transportation. In some parts of the universe transport pads allow instantaneous transit to locations light years distant. Vessels even travel between dimensions to parallel universes to bring back strange new treasures, and sometimes encountering new threats as well. It is doubtless that there are still great generation ships floating throughout the cosmos waiting eventually to find a home. Colonies have been founded, lost to the eons of time, relocated, and subsequently lost again.
Humans have interacted with innumerable alien races. Some are friendly, some not. The human race has both conquered, and been conquered by a multitude of races. Interbreeding, radiation, disease and planetary environments have spawned mutated variants of humanity that have in time become separate race of their own. New races are discovered regularly both by the various alien races, and by humanity themselves.
Great catastrophes have fallen some worlds reducing them to little more than barbarians. The less reputable members of society Pirates, thieves, freedom fighters, and rebels have their corners of the universe where they hide from whatever passes for law enforcement. The local law enforcement in turn attempts to keep local populations free and/or subjugated for their own benefit.
Humans Vs. Terrans
There is a difference between the Race which calls themselves humans, and the true terrans which still inhabit the planet of their birth. The true terrans are rarely seen outside their own world which long ago left the orbit of it's dying star to find a new star to call home. By contrast Humans are found in every corner of the universe in every technological level imaginable.