I fixed the MAA that became my Filmation Hordak when his shoulder peg tore off inside the bicep with super glue and one of the short Transformers metal pins they use in joints. I just drilled it out and glued the pin in each piece, and that completely fixed it, and it still is perfectly fine over a year later.
But I would assume a thicker plastic peg would work just as good assuming the joint is not overly tight. But the metal pin will not shear off. In fact I have to fix my sons Cringer, the tail broke off.