I'd just go 4-1 and let the Turbine draw from all 4 cylinders.
It don't agree that the design intent of most divided turbines is that 1 side only see 2 pulses per cycle.
Wouldn't 4 pulses, equally spaced,divided to each half of the merge be the intent of the divided housings? It's fairly common on the ricer crap.
The S366's are a little on the largish side, size wise, with the .91 AR. Just trying to optimize spool characteristics.