How to win in DQ4:
1. Have Alena in your party.
2. Point Alena in the general direction of whatever you're fighting.
3. ?????
4. Roll credits.
Ok I'm exaggerating but also not really?
You really weren't exaggerating! I think original DQIV may honestly be the easiest game in the series, as long as you are using Alena with a double attack build. I threw myself at the final boss last night after muddling through the dungeon before it just to see whether or not it would work, and it went down extremely effortlessly. I feel like they went extremely gentle on the balance to make up for the lack of control. The all party healing of the Philosopher's Stone found in the dungeon before the final boss is also overpowered relative to the damage even the final boss can deal. Once you have that, the game is basically over. This isn't a complaint, just an observation. I think this was probably the choice for a game without direct party control.
I was worried about the AI party members because I'd heard so many people mention frustration Clift casting instant death spells against bosses instead of healing, but I never had any real problems with the AI. Yes, this does happen, but it's not as bad as I've heard, because the game does implement a simple per enemy AI learning system.
I was looking at the JPN instruction book to see what information a person buying the game with no information at release would have, and I was surprised to see this mentioned, both because it seemed like it would be hard to implement at the time and also because I hadn't heard of it before. Apparently, party members learn enemy resistances and start to act accordingly based on how many rounds of combat they've had with that enemy. So, it's not that Clift will learn to stop casting instant death spells on an enemy once it's failed enough times, but rather simply that Clift will stop casting instant death spells on an enemy once X rounds have passed. (Maybe it's not so much that he'll stop 100%, but that the probability will become extremely low...) This AI training is retained, so if a boss is hard, dying to it once with your preferred party will make the next try easier, because your companies will go in with more optimized actions from the start.
I'll also say, for all the memes about his useless instant death spells I've seen over the years, in practice I found Clift to be extremely useful, because
he can cast instant death spells, very few enemies resist them, and because of the AI learning system eventually he starts to consistently instantly erase any enemy that he can.
In some of the long Japanese articles talking about this, I also saw a funny explanation for why Minea basically never heals: her AI for healing prioritizing is bugged to reference Alena's value on the table, and Alena was given a value that told her only to heal in absolute emergencies.
Another funny quirk of this system: In an encounter designated as boss fight, the tactic to tell your party to take a balanced approach and the tactic to tell your party to go all out offensively both secretly default to a "Boss Fight" tactic. So, switching between those does nothing. If you want to be more defensive, you have to switch to the defensive/healing tactic.