General rule number one: all other things being equal, a 30" scale bass will be lower tension than a 34" scale bass (i.e. if at same pitch, and same string mass per unit length).
But, general rule number two: all other things being equal, the shorter the string you are plucking the less compliant it will be - especially if you get nearer to the bridge - even though tension on a string remains the same all along its length.
Hence, a 30" scale bass might be lower tension than the 34" scale yet be experienced as less compliant.