Was Crocodile stronger at Marineford? Or was he holding back in Alabasta?

 During the Alabasta arc, Crocodile displayed a level of power that was initially considered overwhelming by the Straw Hat Pirates. He possessed the Logia-type Devil Fruit called the Suna Suna no Mi (Sand-Sand Fruit), which granted him the ability to control and transform into sand. He had a reputation as a Shichibukai and controlled the desert kingdom of Alabasta from the shadows. His strength was showcased through his battles with Luffy and others. At Marineford, Crocodile was present as part of the war that took place at Marine Headquarters. While he did participate in the battle, he didn't display the same level of dominance as some other powerful characters present. This has led fans to speculate that he might not have been as strong as initially portrayed in Alabasta. It's important to note that power scaling and character abilities can be subject to interpretation and development by the author. Oda often keeps details deliberately open-ended to keep the story intriguing.

What is an example of something that has not changed much since ancient Rome’s time period?

 One example of something that has not changed much since ancient Rome's time period is the concept of a republic, or a form of government in which the people have a say in the decisions that are made. The Roman Republic, which was established in 509 BCE, was one of the first republics in history and served as a model for later republics.

The principles of the Roman Republic, such as the rule of law, the separation of powers, and the idea of representation, are still reflected in modern democratic republics today. While the details of how these principles are implemented have changed over time, the basic concept of a republic as a form of government has remained largely unchanged since ancient Rome.