As this game is an Early Access title with all its possible flaws and broken code you should try the trainer on a new campaign.
Unfortunately that didn't work, I started a new campaign with the same failed results, this is the first time that I recall that I have had such a hard time getting a trainer to work, maybe when they finally get this thing released it will make a difference.
But again thank you for all the effort in trying to get this thing to work for me, I am sure you have nothing else to do.
the trainer gives you massive numbers of units so you can defeat opposing units easily.
However you can set it to whatever value you like using the trainer custom ability.
F6:Set Massive Units:999999:
change the 999999 in the trainer