The de Havilland Hornet had handed Merlins that rotated inwards at the top. This was to reduce that asymmetric efforts of losing an engine in the same way as the P38 prototypes. However on the Hornet this didn't give rise to the stability problems that the P38 had. In fact, it could hold it's own with single engine fighters of it's day on one engine alone.
A slim fuselage with a single rudder compared with twin booms and two rudders directly behind the propellors seems to be a good a reason as any.