Perhaps? But I do plenty of projects where I'm just paired with another engineer. I'm maybe taking lead, but they're sitting in on all the meetings and helping make decisions when I want someone to check my work. That may be worth noting in a ticket in case I'm busy or out of office and someone needs an answer around the project, even if they don't have a specific task they're responsible for that they'd be assigned a child ticket for.

It's also a level of precision question. At some point, having a lot of child tickets is just extra work if it's mostly just documenting something that could have been as easily documented by attaching another person's name to the parent ticket.