An important question is how thoroughly they prepared for various party combinations. Most CRPGs are extremely unforgiving if you can't pick locks - most locks don't have keys, breaking containers damages the treasure inside etc.. Most CRPGs are not at all kind to a party that doesn't have a cleric type - enemies or situations inflicting punishing status ailments to multiple party members on the assumption that the cleric can fix it, restrictions on rest, etc.. DOS2 was set up so that any character could play any role, so it wasn't a big deal if you preferred Red Prince or Beast, but if you don't like Astarion, you don't have a rogue (unless you are one, or force a multiclass that interferes with the progression of the class you actually wanted that person to take). I haven't played 5E, but the only ways I see in the PH to get proficiency in thieves' tools are a) be a rogue or b) take the criminal background. There is precisely one character with healing spells. In BG2 you were stuck with a particular grouping for a while, but there were numerous party members to fill every role. The rather strong impression I get is that the origin characters are it for companions. I won't call this a deal breaker, but it is somewhat concerning.
