This diagram is absolute nonsence, but it is actually valid. like you can write rubbish code in any language you can do s with diagrams as well. I think the compiler will pick on this due to parameter conflicts, but yet again – these are made by you. This was just a mock up I made to test connection points – the objective with connection points are to control the visual aspect of lines to make diagrams look prettier (more readable) if needed. I am more interested in giving the programmer opportunities than fixating on rules. You have to learn the tool and know what your doing as in any other tool.