There is no reason for a rogue hireling to do anything but traps. If the devs put points into anything other than constitution and intelligence they did something wrong. If they didn't max search, disable and open lock (and take the enhancements) they did something wrong. If the rogue has a prestige other than mechanic they did something wrong. If these rogues that you pay TP for do not have a +7 search and disable item and a +5 thieves tools then something was missed.
Or they could have just put their skills into the description. It would be nice if it stated "this rogue has 22 search and 5 disable device" when you go to buy it so you don't waste your time in the quest and your TP on something useless.