<Snipped quote by Antarctic Termite>
I'd call them all contrivances, for a start. This feeds into my feeling that the domain system has always been something to bend, break, and work around rather than a mechanic that was enjoyable by any means. Your response there also doesn't address my distaste for how they force you to lump added portfolios in with the same general theme instead of truly branching out.
Why shouldn't a newly created god simply be allowed to have 1-3 portfolios that could be closely related, unrelated, or even in opposition with one another?
Just because something forces bending, breaking and working around it does not mean it is bad, especially in something where there is more fun in the journey than in the destination. The use of Domain + Portfolio is one of the key factors that differentiates Divinus from other Divine RPs, I also particularly think its one of the things that helped us to have such a unique pantheon vs the overall genericness you can see in similar systems.
It allows enough mutability so the characters are not stuck with their initial concepts, but it places enough limits to encourage creative thinking and close the easy path to commonplace concepts that other RPs are filled with.