Your idea reminds me of the start of 1.0, where the player was literally thrown into pseudo-boss fight within a minute of starting, although it was more a tutorial of how the battle system worked, in that you had npcs to help you who would heal you and buff you up, plus the fight was so ridiculously easy as it is you would have to do something monumentally stupid (as in, deliberately trying to get yourself killed) in order to fail.).

In fact, how ARR starts for a new player/1.0 character who didn't get the Legacy opening, it looked like it was going to be the more or less the same, when the carriage/ferry is attacked by beastmen/pirates I thought the player would be thrown into a tutorial battle like in 1.0. I was sadly disappointed this was not the case, and the ferry/carriage manages to evade the attackers.