Sega has almost always operated its arcade operations with a high-low mix. examples:
the standard System 16 board and higher end Super Scaler boards with 2 or 3 68000s,
System 16/18/24 and System 32
ST-V and Model 2
Model 2 and Model 3
NAOMI and NAOMI 2
seems that Sega-Sammy is again going with a high-low mix.
namco did the same with System 22 and System 11, then System 12 and System 23.
the U.S. military often operates like this. complex and powerful F-15s on the highend plus a larger number of cheaper, simpler F-16s on the lowend.
PowerVR has always had the advantage of scalablilty. with their first generation series, they had plans to use single chip versions in PC cards and consoles, providing N64-class or somewhat better performance, and 4 chip solutions for arcades, providing roughly Model 3 performance. (Namco's cancelled System 33 board).