Yes, there are ways around the 5 chip limit as you state. In addition to what you state there is having others buy for someone. I have no first hand knowledge about how many Harrah's puts on the tables. I'll take your word that it is 50%. Still the limit is there though locals / visitors / dealers have more ways to circumvent the restriction.
Note again that my point was that the limit was there for everyone and did not address any of the other issues including the reason the policy is in place & work arounds.