Having come from an Ironman triathlon background to racing points/scratch/pursuits (I did race sprints the first few years even making the State Masters Sprint quarter finals but sprints didn't really suit or interest me); focus needed to be on level 4 (FTP) and especially above intervals when training by solo. If you are like I was, you will be a diesel and able to chug along at a good pace for hours so you will need to work on your ability to power above threshold and recover quickly before the next sprint or counter attack.
In group training I find whistle sprints are great at replicating the attacks and counter attacks of the enduro events. Then I also recommend racing as much as you can - for the skills and tactics plus racing as the best training for racing!