Btw, are the mechs technically robots or just very large exo suits 
In the universe units are divided into a few categorys
Infantry: Pure cannon fodder although they can be nasty in a city fight if you don't have the right mechs or support elements to fight them
Battle Armour: Infantry in an armoured battlesuit equipped with a variety of half decent weapons varies in power from some of the medicore innersphere suits to the OHSHIT were dead clan elementals
Tanks: Varies in size from 5 tons to 100 tons mounts mech grade weapons but tend not to be as manoeuvrable or as well protected
Mechs: Giant stompy robots with big guns the backbome of your army in the setting. Comes in 4 flavours light medium Heavy and assault
Light: 20 to 35 tons Scouting anti infantry and raider mechs usually a small amount of weapons thin armour and good speed
Medium: 40-55 tons Jack of all trades master of none does a bit of scouting raiding and can also stand in the battle line generally your average giant stompy robot
Heavy: 60-75 tons your basic line of battle mech good armour average speed and a good selection of weapons this is the mech type you want most of ideally
Assault 75-100 the heaviest of the heavies Slow with tons of armour and the biggest guns you can buy what you use when there is something really important you want to capture/defend
Proto Mechs: A clan invention that combines the paper thin armour of Battle armour with the firepower of mechs never used them much myself but they have a reputation of being mostly crap
Aerospace Fighters: The fly boys equipped with all sorts of weaponry that ranges from peashooters to OSHIT levels but rarer and more expensive even than mechs
