I've tried that the first 3 times and it got a bit confusing right away
You should find the Youtuber "rahdo". He does some board game demos with himself as two players. Not four players, but in some of those board games, two players is already way more than a person should manage.
On a side note, I play many card games by myself as 3-4 players. I am referring to the classic card games with the 52 cards.