Step 1.
I figured out how to add these models. In the merged.lsx file add this line:
Azer Warhammer: <attribute id="ParentTemplateId" type="FixedString" value="22baa548-56a4-494c-a9d0-4880d6f1da91" />
Djinni Scimitar: <attribute id="ParentTemplateId" type="FixedString" value="96f7647b-7485-4c0c-aaad-73a332d8e626" />
Step 2.
remove this line: <attribute id="VisualTemplate"
Step 3.
PROFIT