Actually i think every patch (not main update like new clients download) can be done without new exe files since they only add or minus info from the database. But to fight hackers (actually they don't do but since legit player yell a lot), they might just come with new exe files with the patch so that it stop hackers for a while.
So, if ppl really hack in dungeon or place that are more "hidden" and less ppl complaint abt it, patches with new exe files might not come so soon. (Not some noobs that use skill hacks in public or go pk GM...etc)
And definately most of new hackers wont "clean" up the mobs, they leave the mobs in walls, and some afk hacker doing oread spawn and their babies is all around, just like telling ppl that "oh yeah, catch me if you can"... Risking your high levels character hack in public just get you no where. (Those hack smart are high levels i know that.) You wasting time to level again when you get banned.
Just my opinion.