Some other ways (both with and without pin, but not using compression-only approach) are shown here: CalculiX-Examples/Test/Joints at master · calculix/CalculiX-Examples · GitHub
And, for reference, this is likely the request synt refers to: Quick connection of assembled parts
Ideally, such a tool for simplified pinned joint models could offer multiple approaches. Then the user would select which MPCs (rigid body constraints or kinematic/distributing couplings) and 1D elements (springs/beams/GAP) are used internally (although, it’s usually named more generally such as rigid/flexible).