The pump symbol tells you the control strategy
Fixed or variable displacement, and the arrangement of the control lines, indicate whether the circuit will operate at constant flow with relief dumping, or destroke to demand. That distinction sets both installed power and heat load.
Filtration position tells you what is being protected
Pressure line filtration ahead of a proportional valve exists to protect that valve specifically. Substituting a coarser element because it is cheaper or in stock will shorten the life of the component the filter was there to protect.
Accumulator symbols carry compliance implications
Accumulators bring pressure equipment requirements, safety blocks and pre-charge specification. They are frequently the item on a circuit diagram with the longest documentation trail.
