Okay this is how this maps work for the beta i put together.
Guard Tower = 5k HP, they also get upgrades when you upgrade.
Here is how it works.
Upgrade: Shield to receive Sword upgrades.
Upgrade: Sword to receive Shield upgrades.
Also BE HUMAN i only set it up for HUMANS. I do have another work with both races working and no special towers... but here it is for now.