It depends on the specific fanfiction. In some stories, Superior Iron Man might be more powerful because he's willing to push the limits of his technology and his morals further. But in others, Iron Man could be more powerful due to his experience and his ability to work well with others.
One aspect that could be interesting in such a fanfic is the character development. The members of Team Iron Man, like War Machine, had their own reasons for siding with Iron Man. A fanfic could delve deeper into their relationships and how they were affected by the rift between the two teams. It could also show how Iron Man's technology played a crucial role in their fight against Team Cap. Maybe there could be some cool tech - based solutions to problems that Team Cap created with their more 'freedom - first' approach.
Characterization. It should accurately portray the members of Team Iron Man. For instance, Iron Man is a complex character. He's a genius, billionaire, playboy, philanthropist. A good fanfic would show how these traits influenced his decisions during the conflict with Team Cap. His intelligence led him to see the potential danger of the unregulated Avengers, and his wealth allowed him to develop the tech to combat them if necessary.
Thanos could also win in a fanfiction. He has incredible strength and the power of the Infinity Stones at his disposal. In a lot of fanfictions, the power levels are often exaggerated. Thanos could simply use the Reality Stone to make Iron Man's weapons ineffective or use the Time Stone to freeze Iron Man in time and then defeat him. His brute strength alone is enough to overpower Iron Man in a direct confrontation. And his experience in battles across the universe gives him an advantage over Iron Man who mainly operates on Earth.
In some fanfictions, they might team up against a common enemy that requires both their unique skills. For example, a new super - villain who has the ability to hack into Iron Man's technology and also has super - strength that Spider - Man has to counter with his acrobatic fighting style. They would have to learn to work together, with Iron Man respecting Spider - Man's instincts and Spider - Man learning to trust Iron Man's strategic plans.
In some fanfictions, the winner isn't really about who is more powerful physically or technologically. It could be about who has the stronger will or the better moral compass. For example, if Iron Man realizes that he's in the wrong during the fight, he might back down, making Spider - Man the 'winner' in a sense. Or if Spider - Man is able to convince Iron Man of a greater good, the fight could end without a clear physical victor.
The differences between them are significant. Lex Luthor is more of a traditional villain in the short story. He is jealous of Superman mainly and wants to prove his superiority through his intelligence and inventions. His technology is sometimes more experimental and untested. Iron Man, however, is a hero who has refined his suit over time. His technology is reliable and battle - tested. In terms of character, Iron Man is more self - sacrificing. He is willing to put himself in danger to protect others. Lex Luthor is more concerned with his own status and power. Their methods of achieving their goals are also different. Iron Man uses his technology to directly combat threats, while Lex Luthor may use more underhanded means like manipulation and subterfuge.
Iron Man would probably win. He has a highly advanced suit with a plethora of weapons and defensive systems. His suit is constantly evolving and he has the genius of Tony Stark behind it. Metallo, while strong with his kryptonite - powered body, Iron Man could analyze his weaknesses and use his repulsors, missiles and other gadgets to take him down.
One interesting plot could be where Metallo somehow gets an upgrade that can disrupt Iron Man's technology. Then Iron Man has to rely on his wits and basic engineering skills to fight back. Another could be a scenario where Iron Man has to protect a city from Metallo without using his full - powered suit, making it a more challenging fight.
The cap man and monkey story is an interesting one. There was this cap man who was traveling around selling his caps. He reached a place near a forest and decided to take a rest under a tree. While he was sleeping, the monkeys in the tree noticed the caps. They climbed down, grabbed the caps, and went back up the tree. When the man woke up, he was confused at first, then saw the monkeys with his caps. He was worried as those caps were his livelihood. But then he remembered that monkeys often mimic human actions. So he took off his own cap and tossed it. The monkeys, being the imitators they are, did the same with the caps they had taken, and the cap man got his caps back.