So what have I done, well firstly I cleaned up the plastic bits and removed the glue that was clogged round them, then I covered their base in PVAcrete to see them more securely to the base. I also repositioned the plastic bits so they were nearer the edge of the base to allow troops to move through, if they are 10 mm that is anyway.
Glued on with a hot glue gun, doesn't give a good finish though.
The whole join covered with sand and wood glue, PVAcrete.
Finally painted black to fit in with rest of base. Its a more attractive join and its far stronger, just takes a while to do. Seven more to complete today.