National Step Challenge Can it be Completed?

I joined and faithfully completed National Step Challenge season 4.  I continue to join Season 5. Season 5 added 2 more tiers to MVPA in Season 5 when I started the season, I was thrown back to Season 4 MVPA tier 5. So my Season 5 cannot start huh? Am I a completer then?

On calculating the time needed to complete 6 tiers of MVPA, I was surprised that it requires 187 days (40 points a day maximum). The challenge period is 189 days. To start MVPA challenge  I am supposed to complete the steps challenge tier 2. Minus the bonus, It takes at least 37.5 days to complete tier 2 of the step challenge. Adding it to 187 days, it is impossible to complete.

Now that I am thrown back to Season 4, I need another 75 days. It is equivalent to I cannot be a completer in season 5. I decided to quit completely. It is a challenge with a set period so it should start and stop within the period. HPB make it so difficult to complete. I wonder why.

By the way, in Season 4, HPB actually recommends 150 minutes per week for MVPA. That is 5 days of 30 minutes MVPA. Which translate to 200 points. Therefore, to complete the 6 tiers (7500 points), you need 37.5 weeks which is 262.5 days. Another puzzling figure. Absolutely mission impossible.