If you are getting
Carus,
Galerius,
Severus II,
Magnentius,
Gratian, and
Jovian from uncleaned lots, I would say you are having really solid luck or maybe getting your uncleaned coins from a different corner of the Empire than I do.
Like you, I buy lots of uncleaned coins just for the fun of it. I put my headphones on, get out the mechanical
cleaning supplies, and just clean them. It's all pretty Zen I guess. It's rewarding to get to something interesting I can use Forum/Wildwinds/Sear/Helvetica's Tables on to reach a definitive conclusion. My actual areas of interest for true collecting is
Legionary denarii,
Republican denarii, and The Crisis. In uncleaned lots I've
had decent finds (some
denarii of
Titus,
Septimius Severus,
Geta (
limes),
Julia Domna), but that's out of...something like 500 uncleaned coins? I keep
complete records of all of my "finds", but I've never encountered a
Severus II or
Magnentius since I started around 2014. And I seriously doubt that anything truly valuable slips though to the point where I could buy it except in very
rare circumstances. (Although the
Septimius Severus denarii I found was in incredible shape but completely caked in mud and looked like nothing on the outside. That one might have actually gotten through someone sorting the coins. Even it is probably only a $10-$30 coin though).
I'd estimate that 75% of what I can attribute is Constantinian dynasty, Valentinian dynasty,
Claudius II, or
Aurelian.
Probus,
Gallienus, and Licinius probably make up another 10-15% combined. There's nothing wrong with getting coins from these guys, but other than the Crisis emperors, I usually don't even put low grade
LRBs in
flips anymore. I have a little piece of
pottery I place them in as a decor item. I put unattributable early bronze in there, too. I've let a few people take a couple of them as gifts. That said, I'd be stoked to find a
Severus II,
Magnentius,
Carus, or
Galerius because I rarely see those. It makes me think where you buy from actually does matter.