It is possible to mix different batches of LEDs together in one screen, but it is not recommended. Different batches of LEDs can have slightly different colors and intensities, so if they are mixed together, the resulting screen will not be uniform.
It is usually better to use the same batch of LEDs for an entire screen, or at least for an entire row or column of screens. This will ensure that the colors and intensities are consistent across the entire display. If you do need to mix different batches of LEDs together, it is important to do so in a controlled environment and to test the results thoroughly before going into production.