I,
We are talking two different products.
A transformer is designed to take 120 Volts AC and step it down to some low voltage AC. For pool lights, this is normally 12 Volts AC. The Transformer and Accent light you show above both work using 12 Volts AC.
The "Main Pool" light you show above uses 12 volts DC voltage. A transformer cannot, by itself, make DC voltage. That is the purpose of the "LED driver" Power Supply. The power supply changes the 120 volts AC into 12 Volts DC
You can't mix these AC and DC products together.
In the big picture, I suspect that the DC pool light and DC driver/power supply would work fine in your pool. That said, I did not see where they meet the US electrical safety requirements and have no clue if they will pass a US electrical inspection. That does not mean they are not safe, it just means that I don't know enough about them to recommend them. I did notice that the DC power supply did not specifically say they were made for use in a swimming pool.
Thanks,
Jim R.