In my experience this really depends on the type of the team. If it is a product team it is likely to have a lot of junior developers and not too many senior ones. If it is some deep Infra/backend team you can have a team that is mainly >L5. I was surprised when picking a team in FAANG the choices were you either join as a tl of a very large team of junior ish devs or you join as TL of a small team with mainly senior devs.