Yes. Well, the mod did prove that, didn't it? But 8 does make the game SO easy that it is no longer fun.
That said, as mentioned before, it makes sense from a realism standpoint that they should not limit party size at all. Let us decide how many we want to take with us. After all, if I'm going raiding to wipe out a cultist camp, I would probably bring everyone I can.
On the other hand, I think they COULD limit party size in a more story-driven and realistic way. If I brought a party of 7 or more to the goblin camp, maybe have the goblins become more suspicious. "Who are you? Why so many well armed individuals? Seems like you might be thinking of starting something, if you ask me. Think I'll keep my eye on you.".
In other words, after X party limit is reached, people start getting nervous about you and treat you warily. The max size before drawing suspicion would be based on where you are.
So, the player would then have to plan strategically. Do I take more with me and arouse suspicions or take less and if trouble starts I could be in trouble?
That would be cool, but I doubt they have that in them at this point.
That sounds like a great idea really. An insight check and any one of the companions could open a dialog and say "This large of a party will certainly arouse suspicion don't you think? I think if we want to infiltrate, we'd better keep our numbers down." Then you decide and do whatever you want.