From: Winnipeg, MB
Sometimes when you build a unit, it will have a device that was not in the smaller units but the amount will be "0" which is what you need to get as replacements.
Yes, unlike Infantry Regiments, Brigades often have extra artillery and such which might make them the equivalent of a third of a division without any additions to the TOE. Take it on a case by case basis.
Since no one has mentioned pools yet, I advise you to check the Intel Report screen, click on the "Industry/Troops/Resources" hypertext and use the filters at the top to look at the devices for the Nationality and type of unit you are considering. It will show the devices available to that type of unit and how many are in the pools, plus monthly production and replacements available. British and Commonwealth units have quite low production rates so you must try to avoid heavy combat that could leave your units understrength and no replacements available in the pools.
For example, the starting units are usually very inexperienced, poorly led, understrength and poorly supplied and have poor morale. These will need six months to a year to become reasonable fighting units without any combat. If thrown into combat, there is a good chance they will be wiped out. But once they get beyond 50 Experience, get decent leaders, are close to their TOE being filled out and are paired with stand-alone artillery, AA and A/T units they can be decent fighters. First offensive combat should be with very weak enemy units in open terrain if possible. If Defending, have them in good defensive terrain. The idea is to get them "blooded" without losing too many squads. Then their Experience will go up as disablements come back to strength. That is how I envision "being careful" with using these units and protecting the shallow pools.
No matter how bad a situation is, you can always make it worse. - Chris Hadfield : An Astronaut's Guide To Life On Earth