I mean.. does it make any sense? No, but most RPGs out there have a cap on the number of companions you can bring along (DA, ME, NWN, IWD etc). Even in the original BG games, only the cap was at 6.
In my opinion, the best approach is to have a few highly characterised companions who you can bring along all together instead of having tons of them and just travel with the usual 3.

I think Larian has chosen a party of four because is the realistically maximum number of people you can recruit for an online cRPG campaign. They are going for the Multiplayer experience first, sadly, because at the moment we have 5 companions, so a group of six will be more than plausible.

I think was confirmed that not all the characters will make it past Act 1 so, even with the new companions, I think we will have 6-7 of them top.

Not a fan of it, I prefer to venture forward with all my companions, but if I could tolerate it in Dragon Age: Origins, I think I can tolerate it here.

Still, again, not a fan.