Are COIN games too long?

This is not a hot take, I'm not trying to solicit angry responses, I'm just thinking out loud. I'm a big fan of COIN games, when I came across Andean Abyss about ten years ago, I was absolutely mesmerised by it. I bought it, I've got Fire in the Lake, A Distant Plain, All bridges are burning and Red Dust Rebellion. We have a fantastic board game club where we play every Wednesday but COIN games are too long for these 3 hour sessions, so they can only be played a few times every year when we have the all-day long sessions. Every time, we are raring to go and get really excited to start playing but by the end, they almost always feel just a slog, our brains are fried from concentrating for long hours and I always wow never to touch a COIN game ever again. Obviously, a few days later we're already talking about what we would be playing next time :)

Long story short, today, we played Red Dust Rebellion for the very first time. It took us some time to set it up and to get all (or at least most of the) rules clear. However, we let the Church of the Reclaimer run away with it, were too caught up in our own BS and by the time the first Dust Storm came around, we were shocked to conclude that he won. In just two hours, the fastest COIN game we've ever played. After the game, we were all exhilarated, and we vowed to play it again at the next long session. But it got me thinking - wouldn't it make sense for these games to be shorter? Or maybe the historical accuracy would suffer? I'm genuinely curious and it is totally possible that because I haven't played any of the games twice (because they are so difficult to get played due to the length), we are just too slow and the games are to mentally taxing. Genuinely curious what others think.