You move 2 single elements which are finishing as a group. the second element is contacting the front corner edge of a single adversary element.
a - Do we consider that the 2 first are a group and so the opposite single element must conforms to the group ? b - Do you consider that the second element move is illegal and that hîs contact could not occur as a group move contact ?
If the two elements start the bound separately, this would not count as a group move even if they ended up as a group. They could move as a group in the following turn. So if the second element could not end up in legal contact, the contact could not occur. The enemy element would not be obliged to conform.