Very much a case of what works for your body and how used to hours it is. I know I respond well to big miles, whether on the bike or running. Those looking at the 150k week, have a look at my training log on Strava (attached). It has been a steady build to that and no real speed work. This week will be a little easier, next big week will be leading into Loskop. Shorter weeks have more speed and strength(hill work) in them. It is not that hard to get 100km a week in when you do 50-60k on a weekend and still get two rest days. Effectively resting from Sunday morning after run session till Tuesday morning and possibly on friday as well. Massage/Stretching and effective body management plays a massive role as well. You can't expect to run 90km at 4m30 -4m45 you aren't doing the miles and doing some decent speed work. It is obviously very different if the goal is to finish.There are some people out there that perform really well on 80-100km per week and others that need 150km plus weeks. Everybody is different, it is also one of the strongest reasons why I don't use a coach they often have one program which thy slightly adapt for their athletes. Look at Barry and Jess, they are a great example. Both of them knows what works for them and train accordingly and get the best out of themselves. I am lucky that my training/race partner responds in very similar way to me so we can do all our training together. When I was on the bike, my stage race partner I would only do recovery rides or LSD together despite living less than 5km apart. In two years we probably did 10 training sessions together. He responded to different training to me, but we got to races with as close to zero performance difference as you could hope for. It is getting to crunch time for comrades training, all the best to all of you and no getting sick or injured. Stick to your plan.
