Either it would generate a more robust (and likely more recognizable) solution, or it would fail to converge, really. You may need to train on a smaller number

Either it would generate a more robust (and likely more recognizable) solution, or it would fail to converge, really. You may need to train on a smaller number of FPGAs and gradually increase the set. Genetic algorithms have been finicky to get right, and you might find that more devices would massively increase the iteration count