There is some great info on here! A few points that I haven't noticed being discussed:
Seasonal patterns, comfort, and availability/ease of catching prey and basic water conditions are going to dictate behavior and location of fish. For example, pre-spawn through post spawn, you're very rarely going to find 8" bass grouped in with 12"-14" bass and similarly, you're not going to be finding larger 17"-22" bass hanging out with the smaller males except during the actual spawning, and it's extremely unlikely you're going to be finding 8" bass grouped in with those big females while the females are gorging themselves pre-spawn. Similarly, during periods of migration, it's typically larger fish leading the migration.
The rest of the year, bass simply want the most comfortable water that will provide them the most efficient access to food (lowest energy expenditure/calorie intake). The most dominant fish in that body of water will be found in the best places because they are the top of the food chain. Those areas that are the "best" will have the highest concentration of big fish, with smaller fish primarily settling in secondary areas, and so forth. This doesn't just apply for a single species. If a lake has a strong musky, pike, walleye, or largemouth population, those can all effect the best available feeding areas for smallmouth and thus where your smallmouth are going to be located, the frequency larger smallmouth will occur and how close they'll be grouped with smaller smallmouth/ compete with them for the same prey.
If I didn't just make it seem even more complicated, I hope this helps.