Schist has poor permeability, but it might serve as an aquifer if fractured so water could pass. weathered soils derived from schist from what I have seen are highly erodible and unstable when wet, exhibiting slumps and trees leaning from rotational failures. Some schist is fairly competent as a rock (hard), some weathers into what looks like a rock, but is punky, crumbles under scarification or pressure.

Yes it can be like in Arbian shield in Saudi Arabia and Yemen

fractured schist can be source of water in movable or stored form but we can't say it is aquafer of unconfined , confined and semi - confined nature.