Yup, ssystem4 LCD pinout is completely different.
Less likely idiot engineer, more likely smart engineer that optimized the PCB traces to the LCD.

Try getting the 7segs data from RAM maybe?

Achim dumped a Simultano (C version), I'm working on a MAME driver now. LCD is indeed the same as the ones in later Saiteks, not just how the screen looks, but LCD hardware too.