The defense leves in general need to be balanced out. Depending on which leve you take on, sometimes you'll face 1 enemy every 45 seconds for the entire duration, sometimes it'll be 1 enemy and then 2 enemies and then back to 1 and then 3 enemies. Then there are certain ones that will spawn a set of 2 followed by a set of 3 only five seconds later. I've been in defense leves where I'm faced with 5 Fachans at once... how is anyone supposed to solo that without being one of the stronger soloing classes with several cross class abilities?

Not to mention it's practically impossible to get the speed of completion bonus on certain defense leves. Some of them spawn so damn far away from the camp that it takes 45 seconds to a minute WITH Quickstride just to reach the designated area. Then you're looking at 5 minutes for the defense and then if there is an extra set that spawns after that, you'd be very hard pressed to complete it in time.