I've only had the pleasure of playing FM3, my god what a game, what a story! I loved every second of it and I replayed it to hell to get all the different variations on story possible. I also used to do my own challenges. I loved creating Wanzers and getting the most weight - power ratio possible whilst keeping the remaining product attractive on the aesthetic style scale. I also used to spend hours on them combining different weapons and training in the simulator to get different abilities and skills. I used to have a close assault unit for shearing arms/killing pilots (usually a shotgun/melee weapon carrying type where I would utilize mostly kassel m2 parts to keep its hp huge so it could take the brutality of getting close. Sometimes especially against later battles, I would swap the melee for the shield to keep the unit alive longer) Then I'd have a medium range assault type using a machine gun with a melee weapon or a shield for it's second, normally a shield since if the enemy managed to take my close assault out this would literally be the last line of defence for my long range units, should it fall I'd end up with one hell of a problem in the battle. My remaining two would consist of a sniper type which would often forgo secondary hand weapons/shields in order to whack a shoulder rack missile launcher on the opposing shoulder so that it could pretty much rape anything (once available the sniper rifle would be replaced with the beam rifle) and then the second support type would literally be like the black mage of my party utilizing twin rocket launchers on it's shoulders a shield and perhaps a melee fist for if it got ugly though it often stayed safe especially with the backpack packing extra ammo for those rockets so it could just keep pounding anything that moves with salvo or something similar. I don't remember being allowed to use more than 4 units but if I did get to use more than 4 I would generally put an extra assault type in there since getting up close and personal would not only tie up their nearby units it would also provide me with steady supply of wanzers for parts/scrap selling because with a shotgun and melee attacks you could destroy both arms and leave the wanzer all but disabled, surround that after the field is won and eventually the pilot would surrender.

Also dude Hacking and the internet in the game is smurfing amazing!