In a profit share /401k plan there are about 12 highly compensated partners and 2 salary employees low compensation. Contributions of 15% are made to partners and 12% to others. This passes all discrimination testing.

A 3% safe harbor is made to salaried employees effectively bringing them up to 15%. Does this sound correct? I thought the 3% safe harbor could be satisfied by the 12% they are already getting. ( since 12% is greater than 3% )

What would be a reason to go beyond the 12% in order to satisfy safe harbor?