Order is not important, in general, as all candidates are typically 'in the running'. Some say that going first means that you have to set the bar for the others, and if there is a long time between first and last, the memory of your brilliant performance may fade. Others posit that going last allows you to capitalize on the learning curve experienced by the SC.
Bottom line, just go whenever you can, and as as Alexy Brodovitch would say, "Be brilliant."
This was quite true for the committee a friend just served on. After the first candidate visited, they raved and raved about him. Then the second candidate came and they were equally impressed by her. She held a distinct advantage because she was fresh in their minds. This university video-taped the job talks and uploaded them. The SC was encouraged to view them once again before making the final decision. I know this is purely anecdotal, but I think there might be an advantage to being last. The SC has hit a stride and the presentations/time spent is fresh in their mind.