Oil substitution for butter in pastry recipe
Traditional Cornish Pasty pastry is made with 1 part strong bread flour, 1/4 part each of butter and lard, about 1/3 part water, and about 1% of the flour's weight in salt. The pastry is worked quite hard, almost like a bread dough, and left to rest for a good hour. The resulting pastry is leathery enough to withstand a miner's pocket, faintly crisp on the outside, (with an egg-wash), and slightly gooey where it meets the filling ingredients, which are introduced raw, and cooked in the pastry.

Doing the sums, that's about 450g of fat to a kilo of flour,and 380g of water. Bread flour is 12-15% protein, higher than yours. The stronger your flour mixture, the more pliable the result.. the more oil, the more prone to crumbling (pure oil> shortbread.. pure water>something like a salt crust which it might take a hammer to break)

If I was experimenting with oils, I would combine the oil with the flour first, (probably in a food processor - it doesn't matter if it's overworked) and introduce the water slowly, until a coherent ball is formed, bearing in mind the paste will become more pliable after resting.

For a Cornish Pasty, the paste is rolled quite thick, about 5mm, cut with a dinner-plate as a guide, back half flopped over the pin to be filled, then folded over, and crimped.

Forgive me if I've misunderstood what you mean by 'Pasty' .. but then, I come from that part of the world.. :)  But it might, anyway, be an informative parallel to the kind of pasty you're aiming for.