Will there be an exclusion that does not allow worker/witness/delegates to be from the same account/address? If someone is going to fill more than one of those roles simultaneously there should be clear separation on the chain as well.
I can understand worker and witness being the same person. They'd be like the backbone delegates we have now. However I can understand why being a delegate and either of the two other roles at the same time would be a conflict of interest.
It's going to be interesting to see how the community chooses to handle that. Perhaps it's better to allow all proposals to be brought forward and allow all of it be openly considered. Otherwise I it could lead to a culture of sock-puppets and arms-length affiliated operators within the ecosystem. At the end of the day, even if they are in all spaces, they are still just one of many who can provide check and balance as well.
Perhaps in situations like that then a multi-sig is standard.. or maybe the multi-sig being the standard for all then conflict becomes moot.
I think Pheonike regarding separate accounts is good at least to make the accounting easier for everyone to follow. I don't know though in regards to splitting their voting power.. because then their stake will be halfed or thirded if I am understanding what you are suggesting correctly.