I don't take their explanation at face value. I think you very well could be right in your analysis here.
It is more interesting to me that actual targeting is based on trade imbalance. They could easily have used the same rhetoric and targeted the tariffs based on something else. I think the way they are targeted is sufficient to rule out a lot of explanations I have seen proposed like I mentioned above. What you are mentioning seems super plausible to me I just can't be sure yet.
You hit the nail on the head with the targeting. Trump has a long held obsession with tariffs based on an inability to understand that trade isn't a competition where if you buy more stuff you lose.
It's arguments about tariffs as a revenue source replacing other taxes which are ancillary ones thrown out to appeal to other vaguely Republican instincts. Obviously if the US actually wanted to use them as a revenue source they wouldn't set them at punitively high rates likely to simply eliminate trade, frame it as a battle to reduce import dependency or dangle the carrot of trade deals to anyone willing to bend the knee. Not to mention his rapid reverse ferret reframing it as focusing on China