The question "is it accurate" can only be answered if you define the scope of the analysis, the "simulation question". It is accurate if the main subject of the analysis is the frame, and not precisely in the red regions. But certainly the detailed distribution of stress in the connecting surfaces, and the exact natural frequencies and modes of the system, they could certainly be a little different. Also, an important point is if you define the connection as flexible or rigid (infinitely stiff). For mechanical assemblies, I find the "flexible" connection more realistic, but you have to judge based on reality.