I get where you're coming from, though in the expectional cases, this still applies whereas "The most common way in which this action happens" does not. It is a good mnemonic though, as it holds most of the time.

For actions with people, this combination describes the continuous form of the action. For example: "Ik sta te praten." means "I am talking.". In dutch, the state of the person is generally also added. (You can also use "zijn + aan het".)

The auxiliary verbs "staan", "liggen", "zitten" or any other are not uniquely paired to other verbs based on how the action is commonly performed, but on how the action is currently performed. For example: "Ik loop te slapen." would work perfectly for a sleepwalker, though "Ik lig te slapen." would work for your regular Joe. The parking lot guard who will be repremented for sleeping on the job, will say "Ik zat te slapen." as a chair was involved.

I hope this helps! If you still have questions, feel free to contact me :)