Direction changes how a result reads. An address that sent funds to a scam is often a victim, while one that received scam proceeds sits closer to the laundering side. Some tools phrase the same idea from the counterparty's view: receive risk means it is risky to accept funds from the address, send risk means it is risky to pay it.
Report the two directions separately. Adding them does not produce a unique-funds total, because money received from a risk source and later sent to one counts in both.