Scenario:

I'm playing SCH and I'm with my boy, a BLM. As soon as i start Adloing him from behind cover (LoS the enemy), and he begins to have free casts, he will absolutely destroy everything.

If you look at the party list when you join a Frontlines match, its usually full of ranged DPS. Melee DPS just had to be buffed in the recent patch. People complain about a lot of little mechanics in this game, SPRINT consuming tp , Instant- Interrupt, Melee Positional Requirements, HEALERS, crippling CC, CC diminishing returns. It's all about learning how to dance. Its because of these weird idiosyncrasies that the PVP system has its own strange take on positioning that fits with how its own servers and class design work.