wxy, they are all able to be flown single pilot. It is countries regulations that stop them from being flown single pilot in air transport operations.
@93K
If you went to work for a operator who flies something like C421's or other "High performance" planes with time on something like a cherokee, and think you have an entitlement to fly them... just because you have "high performance time", then yes, you will get laughed out of the building.
Ok maybe not that harsh, but the guys who do the hiring weren't born yesterday, and they know what a cherokee is, and what it counts for.