This could be easily mitigated by copying Wargaming and putting in rewards for killing said mech/weightclass with a different mech/weightclass. In WoW for example, if they have an event for Battleships, they also put in goals to kill Battleships. That way the playerbase stays relatively even across the classes.
Would go a long way to lowering wait times, complaint threads, and gives everyone else who doesn't have said mech/weight class something to do too.
