>>23462339
the modeler is fucking retarded, the shoulder is that loose because he didn't fully push it in along withe the arm, just look at the gaps

the shoulder connector is the same as the Dark Matter and the Exia, it needs the arm has a coonector that fits the shoulder connector piece.

TL;DR: it is working as inteded, the modeler is shit or misrepresenting the kit because he is retarded