To expound, PvE is like UO. Mobs are more there for resource extraction than the difficulty itself. It's an efficiency model, rather than a difficulty model--more about how quick and efficient you can burn through mobs. The combat is action oriented and skill based, so there is probably going to be a VERY large range of efficiency. And that will separate mediocre players from really good ones--not being able to defeat mob X but rather a great player can kill 50 of mob X while a mediocre one can only kill 10 in a given time period (And so the great player is able to grind more experience, and resources. Since there is only a soft level cap, the carrot is always there for this). Even the huge bosses you CAN summon are mostly damage sponges, and DPS checks (Ensuring you have enough people working together to take them).