Unlike the first time, where I modelled axis 1 through 5 almost to a "render ready" state, I've just jointed motors to motors with air holding the model together. You're going to have to imagine that there are beams in the middle.
I wanted to see if I could get a 160x160x80mm solution, and i was so close but there's an intersection on the corner of Axis 3's motor when in this specific pose. I was planning on only mounting Axis 5 with 2 screws instead of 4, hoping that the ouput part of the harmonic drive will be strong enough for the job:
I stretched the arms to the maximum allowable length, which was 114mm, and it seemed like I was going to get away with it too.
I was hoping that I could use the lighter tile and shorter arm lengths to my advantage to have faster animations at the end of the day, but it does look like 160mm is just a tad too small and I will have to go to the P3 panels.