I currently have two types of bugs in my indoor succulents. I would appreciate some help identifying them and recommendations on how to get rid of them.

I don't actually see the bugs on my plants, only in the saucers after I water the plants. Maybe it is because they are really small, barely visible with the naked eye, or maybe the bugs live in the medium. See picture below; for scale, the crisscross pattern is the shade of the window screen. If it helps, I live in Coastal Southern California.

I mainly see the round ones indicated by the blue arrow. They are moving slowly. Most are a deep red/brown color, but some are whitish. I tried getting rid of them with insecticidal soap, without much effect. I then tried horticultural oil. It was more effective, but after two applications I still see many, and some of my plants did not appreciate the treatment, so I hesitate continuing.

After the application of the horticultural oil, I also saw a few of the bugs indicated by the green arrow. They are oblong and beige. All of those I see seem to be dying.

Right now my hypothesis is that the oblong bugs are a type of thrip, while the round one are a kind of mite. Do people here with more experience have a different opinion? Is it possible that the round ones are predatory mites and that getting rid of the thrips will eventually get rid of the mites?

Do you have recommendations on how to treat? As I write above, I tried insecticidal soap without much effect, and two horticultural oil applications has had some effect but it is also taking a toll on my plants and I worry I will kill them before being able to get rid of the bugs. Therefore, I am ready to graduate to a chemical solution.

Thank you for your help!