I calculated a simple example. Two objects are in a circular low orbit but in different planes. The impact velocity depends on the angle between the orbit planes. I use 7.8 km/s for the speed in orbit.
For an angle of 5° the vectorial velocity difference is 0.3468 km/s, for 10 ° 01.6836 km/s, for 15 ° 12.0204 km/s, for 30 °2° 4.0204 km/s, for 45 ° 25.9896 km/s and for 90 ° 511.5204 km/s.
Two orbits with an angle difference of 45 ° to the equatorial plane in oppositional directions have an angle difference of 90 ° between them.
Impact velocities of 1 to 511 km/s are possible.