The first day I would build
Give the city one clear route before adding extras.
- Start with Keyuan Garden and Opium War Museum while energy is high.
- Use Humen as the natural reset instead of crossing town too early.
the easier plan is Keyuan and Guancheng together, Humen history separately, Songshan Lake as a green outing. That keeps the day readable instead of turning every good name into a separate detour.
I would rather leave one place for tomorrow than drag a tired route through Dongguan Central Square just because it looked close on a map.