TSS declining towards season

[Rizzi]

Explain to me: Why does the sweet spot base phase HV have a higher TSS than any of the build or specialty plans?

I’m planning out my season, and I noticed that I SSB HV has the highest TSS of any of the plans in build or specialty. Any reason why? I know that TSS isn’t the end of all measuring tools, but if my TSS is supposed to grow as the season goes on, how can I accomplish that with TR? Just repeat SSB and mix in some other workouts that help me specialize?