Laurent admires his mom and is an academic. He also wears her hat as a way to remember her. That's pretty much it. Beyond that they're radically different.
- Miriel's place among the Shepherds isn't elaborated on. She keeps to herself a lot of the time and provides magic support when needed. Meanwhile Laurent has a very clear role among the child characters as the one who keeps tabs on everyone's health and finances.
- Miriel struggles to fit in among the Shepherds due to her standoffishness and focus on her studies, making her impersonal. Laurent, however, isolates himself because something went horribly, traumatically wrong during the time travel process, causing him to get sent back in time years earlier than the rest of the children. He was left completely alone for years in an unfamiliar time, and as a result he's much older than even Lucina, who was the oldest before they went back, due to the time discrepancy. As such, he feels out of touch. Notably, however, Gerome opens up more easily to him.
- Miriel only focuses on what's practical, while Laurent enjoys more frivolous scientific and magical feats, like gimmick spells in his Robin support, simply due to the lack of such joys in the future. Miriel's no-nonsense personality makes this a stark contrast.
- Also his Noire support implies he might be a bit of a masochist and that's honestly kind of hilarious.
Lucina beats him out, ultimately, but Laurent is easily my second favorite of the Awakening child characters, tied with Owain and right above Inigo. He's a really underappreciated character.