Classic mode by itself already plays a different mindset than casual though. There is no punishment for mistakes in casual, just losing a bit of EXP because that unit isn't usable for the rest of the battle (which usually doesn't matter). In classic, losing that unit means:A) Keep moving on if it's a unit you don't care about, or weren't planning to train.B) You move on with the loss. C) Resetting, and starting over the chapter again. The mindset the player has in the modes is different, much like playing more aggressively on easier difficulties, while playing patiently on the higher ones.
Also, in this mode, I would propose that only killer weapons have crit rates, or remove them altogether. Losing a character because of a crit would just be ugh.