Steps to reproduce.

1. 1.20.1 forge 47.2.1, get tetra 6.1.0, alex's mobs 1.22.6 (will probably work in newer versions too, since no changes were made to kangaroos i believe)
2. Grab a tetra workbench, two hammers, an end rod, some cobble, and the schematic for Warhammers from the creative inventory.
3. Place one of the hammers in the workbench. Change the handle to an end rod by clicking on the handle module -> basic handle -> put the end rod in the slot, click craft.
4. Click on the left hammer head. Click warforge, click craft. Same for the other one.
5. The tool should now have a "Crushing" parameter displayed, which means it should deal >=8 damage regardless of the target's armour.
6. Equip a kangaroo with it and summon a heavily armoured enemy. The effect doesn't work.

The same things works when done with a create deployer, hence I decided to post it here, as it seems that making this work is possible.