I've had various instructors, CPLs with IR, CPLs & PPLs fly with me in a Navajo & a C414 over the last few years. A majority of them couldn't fly the 'straight' part of straight & level. Instead they'd do a very slow & gradual series of 'S' turns. The only time the longitudinal axis was aligned with the required heading was as it crossed it.
No knowledge of the technique of keeping wings level while using the rudder to prevent the heading from moving. Lots & lots of riding brakes against power while taxiing, too.