Start with Basics first or System-based from day 1?

I’m planning a 12-month Step 1 prep while doing final-year clinical rotations, and I’ve noticed people seem really divided on this.
One group says it’s better to start with Basics / General Principles first (biochem, immunology, genetics, pathology, etc.) for the first 1–2 months to build a foundation.
The other group says to start system-based from day 1 (Cardio → Resp → Renal…) and learn the basic concepts integrated within each system.
My concern is that my basic sciences foundation honestly isn’t very strong, so I’m not sure if jumping straight into systems would make things harder, but at the same time I don’t want to spend months on basics and delay UWorld.
For people who passed recently or studied over a long timeline:
If you had to do it again, would you start with basics first or go system-by-system from the beginning? And would you start UWorld immediately or wait?
Would appreciate hearing what actually worked.