One problem with battling the creatures in an environment completely different from the training environment is that you lose the ability to train based on environment variables. In retrospect, a more puzzle-oriented game might have been a better application of this training mechanic. However, having the battleground be an open area would accomplish to this an extent. The only remaining question, then, is how to handle the environment column of training data entries. It seems that, if there is an option whose environment matches this one, that option should be selected, but if there is only an entry with everything but environment matching (during battle), that entry should be chosen.