McKenzie on the best WR

I saw a thread yesterday that said he had to stay on the left side but I don t get why. It is obvious whoever is on Thomas will get the ball so why don't we move them around some so they at least have to look where they are. Upcomming Wr include

SF- Antonio Bryant who is not well known but can definately make the big catch.
Dal- TO is simply to tall and fast for Thomas to cover
Was- Moss can run like Galloway and we remember the TB game don't we.
NYG- Plaxico is their only threat that Thomas can't handle and he is too tall for Thomas
Car. Steve Smith wins games not KJ he is the one that dives out of bounds to get personal fouls.