sam and dean are both complete control freaks as a result of their self hatred but it presents itself in different ways.
sam specifically focuses a lot on self control. its a big reason why i see him as having ocd, but a lot of his personality and behaviors are about keeping himself in check. in the earlier seasons, his struggle with his morality is a lot more emphasized, but he always has this kind of idea of not slipping up. even some of his more average behaviors fit with this (healthy eating, exercise, cleanliness). furthermore, any of his desire to control dean is rooted in this form of self control, either because dean reflects on him, or because of his responsibility as dean's brother. if dean fucks up, it indirectly means sam fucked up, therefore sam must do everything he can to stop dean from fucking up. sam as a character is very self centered, it makes sense that his issues focus on himself.
dean focuses on controlling how people see him. we see dean wear a lot of different masks over the course of the show, altering his identity slightly with whoever he talks to. dean likes to control the narrative. we dont often see the same internal conflicts that sam has within dean, as dean is more focused on other's perception. i would say a lot of dean's personality in this department is from john's influence, especially the military-like training he went through. black and white thinking, toxic masculinity, doing whatever it takes to please your superior. dean is always right, because hes a "good guy". he can't question or unpack it, because that would mean confronting issues that he spends his whole life avoiding. therefore, he must make others see that he is right.
it's interesting to see the ways their issues differ, and i think a lot of it has to do with the ways they were treated by john. sam as a ticking time bomb, dean as a reflection of john.
