It's not possible. There is no good reputation algorithm.
If you solve it (reputation / identification), you solve a much bigger problem than DPOS governance LOL. You'd probably be eligible for a nobel prize.
If you don't solve it, you make noganoo or anyone controlling a good amount of accounts (like @steemmonsters for example) masters of the system via sybil attack.
I really dont know .... also different approaches for different system is needed, and on one to fit them all.
Also a good enough solution will probably be better than nothing.
I think there is some bottom rules that we can all agree and build from there.
One easy example is that a new account cant have big influence. Another example might be that a totally inactive account cant also have big influence .... etc.