Best advice. Players start the game knowing how and why they are going to stick together.
I'm also inclined to put my thumb on the scale a little as DM and give the players a loose connection that they can build on and incorporate into their characters while building. BG3 did it really well - everyone has a tadpole in their head, y'all gonna be mindflayers if you leave the group.
I recently had players all start as fresh recruits in an organisation - they got to decide the organisation - where the higher-ups put them together. Previously I did a one shot at level 5 where players already had an adventuring group together 20 years before and were called back together for one last mission.
I can see making some clans like nosferatu or malk part of some dlc as they have so much unique stuff and presumably require a lot of extra development. I don't imagine that is applicable to toreador though. Also no day one dlc please. If it's ready at launch, if should be in the base game