The answer to your question depends entirely upon your previous training history and base. If you are relatively new to this sort of racing and do not have a really extensive base and experience with this kind of heavy race schedule that’s going to require quite a different approach than someone with 10 years of ultras and many successful races under the belt.
The reason for this is that these races will require some sort taper in advance and some recovery after. Those periods represent training time lost. If you have the experience and base to run a 100mile race then you could probably almost train through the 50 and 62 mile races (treat them like C and B level races). You’d be able to integrate them into your 100mile prep as long runs. You might only need a day or two taper and similar recovery so you they wouldn’t even be hick-ups in the overall training progression. If, on the other hand, you are going to lose a week on either side of these races especially on the recovery side then you’ll need a different approach.
Mike’s big vert plan is designed to prepare you for a single ‘A’ race or major event that represents a significant step up for you or in which you are placing a lot of importance. That’s what the ‘A’ means. Hence all the intensity late in that plan.
Unless you are very experienced you will need to drop back into some lower intensity/high volume weeks between these races. All you can hope to do in 7 weeks (or 5 if you lose 2 weeks out of that to recovery and taper) is to rebuild some base and maybe get in 2-3 uphill interval sessions. I’d assess base fitness after recovering from the 50 and 62 milers. Do this with a one hour AeT uphill time trial. Keep HR under/right at AeT for the full climb. Do this 2 weeks before the 50 when you should be in good shape. The retest 2 weeks before the 62 and then again a few weeks after. If your basic aerobic capacity has dropped off then you can expect worse results in each subsequent race. Doing intensity on top of a slowly eroding aerobic base fitness is not the right approach. You need to keep the aerobic base high and THEN add the intensity. It is a supplement tom not a substitute for, base volume.
As I hope you can see there is no one simple answer. Self assessment will help you see whether you are ready to crush or merely survive.