What do you mean? If they're both circular orbits, they'll have the same period, so they'll never collide—they'll always be on opposite sides of the Earth. In fact, this goes for any two orbits with identical periods.
Debris in a crowded orbit will eventually collide, no matter how synchronized it all was initially.
> Debris between 1 cm and 10 cm (approximately 500,000), referred to as the “lethal” population, are the most concerning as they cannot be tracked or cataloged and can cause catastrophic damage when colliding with a satellite. Objects smaller than 1 cm (approximately 135 million measuring from 1mm to 1cm, and many more smaller than 1 mm) that could disable a satellite upon impact are termed the “risk” population