The workaround against both options is to simply split the stake to different accounts. Both make it more difficult to overtake the chain with a minority stake but it's better than the alternative.
The current setup allows for a 51% attack instead of the theoretical 2/3 +1 that is needed today...that is very clear.
Limiting the number of blockproducers that a stakeholder can determine has other tradeoffs so it's a complex problem.
RE: Fact: Steemit Sybil Attacked the Steem Blockchain