How many checks can the corona engine handle for "collision"

Sorry to bump, any input on the above post, great appreciated! Thanks for your time. I would like to figure out how to always know something in the collision function is always agro.type and something else is always hit.type so I don’t have to do double checks on

if (agro.type == “player” and hit.type == “sMob_2”) or (agro.type == “sMob_2” and hit.type == “player”)then