I did the "local LAN game" trick to create four custom characters, and I was almost immediately struck with decision paralysis. My main character is a Rogue (AT), and I'm taking a Cleric as well, and then I had two slots to decide on some combination of Dwarf Fighter, Human Warlock, and Tiefling Wizard.
Can a Cleric alone be my front-line fighter? If I take the Warlock, how will he be able to see in the dark without the Light cantrip? I eventually went for Rogue/Cleric/Warlock/Wizard, but now I am worried if this is actually viable, because If I'm wrong, there's no way I can fix it later. Especially if I tried it in the full game where the rest of your companions go away.
Some people say that you don't need a dedicated Cleric or Rogue in the party, and you can multi-class and use backgrounds to cover roles... but how are people unfamiliar with D&D 5e supposed to understand the right way to build characters to do that? The choices made at character creation cannot be easily undone.
I really feel like I need at least 5 people in the party to feel comfortable. Four is too small.
In terms of the UI, the game already perfectly handles 6 portraits at the lower left. Lal'ezl and Us were added to my 4-person party without issue.
For the character panels, that's also not impossible to workaround. Display 4 panels as normal, and arrows at the edges so you can shift to show the other two. Like so:
[A B C D]E F [B C D E]F A [C D E F]A B [D E F A]B C [E F A B]C D
You'll still be able to compare any two party members together.