Vouching for more than one person certainly seems to be open to abuse. Also, IMHO, there has to be real consequences for lying. Say a person vouches for another person — and, later on someone else with the same name and address shows up to vote. If that new person can positively ID himself; then person who did the first vouching should be charged with voter fraud, and lying under oath. If the fraudulent voucher IDs the fraudulent voter, that could help reduce his sentence.
it should be a minimum of a gross misdeameanor for one and a felony if mutiple counts involved.