I would say that the 75% shade would be way to much.Really the only plants that like this amount of shade would be some of the paphs and plants that want very very heavy shade. I would have said that 50% shade would have been enough for your requirements.
Just to let you know I grow a larg number of Odontoglossum and most of these want shade- for these I use 50% for the winter as those days are grey and I add a layer of 30% to this for the summer months.This combination gives me 65% .