it is a general fear in game designing to have range DPS outperform or perform equally to Melee DPS with little consequences in almost any game. Partly due to how if a Range DPS outperforms or is equal to a Melee DPS, it lowers the amount of people needing and wanting to play melee DPS beyond the challenge of also being in melee range.
Many past games generally had this issue when range DPS that have little consequence to their performance in anyways outshines a melee dps or are equal to DPS because of the mentality of "why bother beyond just the challenge of being in melee range when you can do the same in range combat and have less risks?"
Don't get me started on how bad things gets in certain games when Meta gets involved between choosing a Range Job that does equal or more damage than a Melee Job. Those tend to go down the hole of Range Jobs being favored and Melee Job only played if you have ultra instincts level of dodging skills to lower risk of losing rDPS from DPS role players dying.
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That aside, the basic concern now is mostly DPS increase for MCH do fit into the role it has been given as the Pure DPS Physical Range job compared to Dancer and Bard which focus partly on maintaining their party buffs.
I say this before in past post but I do see some ideals that can work for MCH from the Blitz job from Dungeon Fighter online.
One such concept is the Bunker wall placement. It can act like MCH's leyline but focus on staying behind it to maintain DPS boost and a damage reduction buff while having a skill that allows MCH to redeploy it during moments when he/she does not need to move around the map often. Not to mention have additional skills that utilize that deployable Bunker wall to act as a 2nd protection from heavy attacks for the party or increase the damage of the MCH even more.
Another addition I think they should utilize is the concept of some kind of Protocol mechanic to improve the Queen's functions. Make them like OGCD skills that instant summons the Queen to perform certain attacks which players can weave into their combos. That or they use each Protocol to summon different drones based on the chess pieces we don't use yet being Knight and pawns to perform certain buffs and attacks
Speaking of Queen, improvements for her can be done to remove the 3 to 4 second summon process. Instead of going through that digitalization summon animation, the Queen should just be summoned by falling from the sky either to punch the target the moment she is summoned with a super hero landing or rider kick them so the Queen can get right into the action instead of the long delay she has currently.
Ammo system can be reintroduced as energy for the Sniper rifle skills to act as MCH strong OGCD attacks so players have to consider what type of Sniper Rifle skills to use if they want to either perform strong AoE on multiple enemies or focus on Single target stronger hits.
Flamethrower has been just bad since release in 4.0. I always felt it will be a better skill as a DoT debuff skill to act as the main DoT skill for MCH while Bioblaster act as a secondary DoT skill for situational moments involving kill large numbers of mobs since Bioblaster shares cooldown with Drill.