So I took a brief look at the build process for Argotlunar and the websites for both, it doesn’t appear these are LADSPA plugins, they appear to be VSTs. Did you get LADSPA versions of these somewhere or are these in fact VSTs? If the latter they probably shouldn’t be in /use/lib/ladspa but instead be in a directory that Ardour searches for VSTs in. As you can see here https://manual.ardour.org/working-with-plugins/getting-plugins/ there are a couple of default locations as well you could try:
Linux VST (LXVST) plugins are distributed as shared library files. They are typically installed in /usr/lib/lxvst, /usr/local/lib/lxvst or a directory mentioned in the local LXVST_PATH environment variable.
The error you are seeing is because Ardour is trying to load them like a LADSPA plugin, because they are in the location for LADSPA plugins, but not finding the LADSPA functions required for those plugins, which is understandable for a VST.