Actually it does.Except this doesn't work. Raven Queen is a god and a warlock patron.
The higher tier beings can offer the lower tier power paths.
The lower tier beings can't offer the higher tier power paths.
A god can make clerics, warlocks, and sorcerers.
A normal devil can make warlocks and sorcerers. A devil needs divinity like Asmodeus to create clerics.
A normal dragon can only make sorcerers. A dragon has to ascend or transform to make warlocks.