hydration of recipe I am using

Hi,

I have a basic sourdough recipe from this forum (the sourdough 101 a tutorial) as follows:

Starter:

115g Starter: I maintain at 75% hydration

128g flour

60g water

Dough:

575g flour

15g salt

360g water 

Giving totals of: 

Flour: 769g

Water: 469g

Which is 60% hydration 

So getting slowly to my question, I use a T65 flour that for yeasted bread I would use at a minimum of 72% but normally 75% hydration.

Are sourdoughs generally lower hydration? 

If I want to up the hydration (which suits the T65) can I do it anywhere in the recipe (I.e. Add extra water when I bring everything together) or is it better to increase the hydration of the culture, the starter dough and the amount added as I bring all the ingredients together?

In short does it matter where the extra water gets added to the recipe?

Thanks