There are many approaches to protecting your pallet rack columns from abuse. Perhaps the best way to find the right solution to your dilema is to evaluate the damage that has been done or what you expect to happen. Virtually nothing will protect from a forklift counterweight (rear) from taking out anything in it's path, so let consider the damage from the working end of the combo (truck & load).
The forklift operators should be carrying the loads close to the floor with some back tilting of the load, so logically rack column interaction will be close to the floor. A little higher if you utilize a "floor" level beam. Likewise, if you use forklifts with outriggers the probable damage area will be low to the floor and if we could protect the rack from the counterweight area of the forklift that will be within 6" due to warehouse truck clearances are only 4-5" depending on brand of forklift.
If the expected damage is from the forks themselves, the attaching column protectors or deflectors may do the job for you. Otherwise, isolating the impact from ever reaching the rack column is desired. Other considerations may include the effectively reduced aisle size, ease of housekeeping, aesthetics, or other considerations the are unique to your operation.