Will my Junior/Senior year schedule be enough?

Yes, it’s got its own terms.
There are three foreign language levels, just like there are three math levels. However because most Americans’ Academic level in foreign language isn’t that great compared to other nations they sent IB, the effects aren’t the same.
FL B HL is similar to what would be a junior-year class in a US college 8
(300-level post AP). FL B SL is roughly AP level. Completing FL ab initio is roughly similar to completing HS FL 3. So students whose FL level sophomore or junior year isn’t up to the rigors of FL B take an ‘ab initio FL’ where they start from scratch and cover 3 years of HS FL in two years.

Unless I’m mistaken with the way this school lists classes, pre IB German 1 wouldn’t lead to German B SL -that’s why I said it’s probably ‘ab initio’ (just a guess).

The schedule is rigorous and should serve the student well for schools such as Colleges that change lives for instance.