wow good tip swordless! And awesome design Spiffers.

Ah, fair. So I just tried this - what I actually ended up doing was moving the arm for the middle assembler up, as you mentioned, then I moved the whole right assembly up (I was able to move the system so it inserted the inputs into the right side of the assembler), so it all nestles even more closely, and even allows me to now use a bent arm for that one.

You can pick up from the side of assemblers. So you could have the arm for the middle one move up and left from where it is and drop onto the same bit of belt. Then the third assembler could produce to the left and you can move that arm over meaning you can get rid of one section of belt. Might shave an extra couple of seconds off. :)