"...for that you need 2/3 +1..."

No. All you need is 51% of stake voting. That is what determines how many witnesses control consensus.

Worse, the weight of stake is currently subject to vast multiplication via the 30 votes availed stakeholders. To wit:

User A has 1M Steem. Casting 30 witness votes worth 1M Steem each gives them 30M Steem influence on governance. User B has 100 Steem. Casting 30 witness votes gives them 3000 Steem influence on governance.

The difference between the stake held by these users is 999,900 Steem. The difference between their influence on governance is 29,997,000 Steem. This multiplication of stake weight dramatically centralizes influence on governance, which consensus witnesses have failed to previously resolve.

Clearly, this is a problem, and strongly lends support to accusations of corruption of Steem governance. It's long past time for this deception and centralization of Steem governance to end - possibly too late to save the Steem community from the Sybil attack it has promoted. Other limitations on stake influence on governance is necessary, but accurate weighting of stake influencing governance is absolutely a necessary component of securing Steem from Sybil attacks.

I am provided estimates of Tron's present stake of ~100M Steem. This theoretically enables Tron to deploy 3B Steem influence on governance. That is utterly untenable now, or ever.