Ryland exhaust pulses only matter until the collector merge section, of the header/s, or to the turbo. Each cylinder fires at a different time and pushes out exhaust at a different time, "pulses". Different pairing of the exhaust from each cylinder can make a big difference the efficiency of the exhaust as you suggest.
The length of the exhaust runners matters if the car has optimized header/s. If the car is non turbo a good amount of gains power wise can be found in exhaust runner length and size. That said there is generally only a certain rpm band that can benefit from this tuning. Most factory manifolds don't care about this in there design. Especially those with a pre-cat. After the collector, benefits could be had from little or no exhaust. Things like proper pipe diameter and good collector design (RPM where you want the power) will be important otherwise you might find negative results with a short exhaust.
If we are talking about exhaust length after the collector in an N/A car you want no bends or interference, straight pipes. If you can't get that then you want the smoothest bends (mandrel) and no reductions or snaking mufflers (yeah ricer like straight thru mufflers). Side exiting exhausts with resonator style mufflers tend to do this well.
And for a turbo car no exhaust after the turbo is ideal, and backpressure has more of an effect. On my turbo Nissan I put an electric exhaust cut out right after the turbo (0 backpressure) for a while. Fuel economy and power improved through the entire RPM range
as did noise
. While this was a lot of fun it might not be for everyone. The car you might see with exhausts through the front bumper are most likely all turbo cars.
So the short version is if you design everything right, short is generally better.