Why schools differ
Feng Shui is not one uniform technique. Different lineages ask different questions, use different inputs and work at different spatial or temporal levels, so apparently conflicting advice may come from distinct methods.
Form approaches
Form-based analysis observes land, roads, water, building shape, protection, exposure, entrances and internal circulation. Many of these observations can be discussed without a precise compass bearing.
Compass and time methods
Compass-based systems use orientation and direction. Xuan Kong Flying Stars adds construction or major-renovation periods and changing time cycles, which makes accurate measurement and dates important.
How to compare advice
Ask which school is being used, what data it requires, whether the conclusion is general or method-specific, and what evidence would change it. Combining rules from unrelated systems without explanation creates false certainty.
Professional method
A report should state its method, inputs, assumptions and limits before presenting recommendations. Methodological transparency is more valuable than claiming that one lineage is the only correct one.