Factories

I’ve just unlocked oil and made my first oil power plant and I have a lot more power to play with now. I’ve done some exploring and found a few pure nodes for a few different ores.

Do I make the factories of the selected ores and make the items there and store them there, or do I connect them to make one big storage depot or finally do I wait until I unlock trains to make it all easier. I’ve got about 45 hours playing the game so I’m still quite new can I have some opinions please thanks.