@eosnewyork your interpretation of article XI might be misunderstood.
"To change or add an Article, voters must sustain >10% voting for 30 days within a 120 day period. "
it states that to make a change we need 15% of all existing tokens (just like the validation of the mainnet) and no lesser than 10% out of the 15% should be YES to be approved. which makes it 66.666666% of total votes.