Robbi, I call your style of cheesemaking Farmstead. What you are doing is perfectly acceptable however, as you have figured out, the types and ratios of bacteria are subject to change. So getting consistent results and "tweaking" can be challenging. I am a microbiologist by education, and a cheesemaker by trade, so IMHO it is difficult to get exact results if you don't know which bacteria that you are starting with. And because you are always using more or less the same native bacteria for every cheese, it is very difficult to tweak recipes and alter your flavor profiles. With commercial cultures, you can add a little of this and a little of that to get predictable results. For example, you have no way to change bacteria for a Gouda vs Cheddar vs Swiss.
The category of bacteria that you are almost entirely eliminating are the Thermophiles. Because you are incubating your starter cultures at lower temperatures, the mid-temperature loving bacteria, Mesophiles, will always be dominant. That makes it very difficult to produce cheeses like Swiss, Parmesan, Gruyere, etc.
What 5 types of cheese are you making?
Now, that being said, there are traditional cheesemakers all over the world that rely on native bacteria and do not use commercial cultures. I have watched cheesemakers in Italy who let their fresh milk sit overnight to allow native bacteria to grow. Then they add some whey left from the previous day's make to increase the bacteria population. They've been making cheese like this for a long time so it obviously works.
If you and your family are happy with your results, then don't worry about what other people think.