Walker is mainly a RB, tho he has played CB for England youth teams too... he may occasionally fill in at LB for a Championship side but it doesnt make him 1 by definition...
I believe a chap called Gareth Bale got lumbered with the label of LB too, after he unwittingly agreed to cover the LB slot after Southampton's regular LB was on long-term medical-leave.... it took him yrs to shake off the tag apparently and is now playing back in his always favoured natural position at LM.... not doing too badly apparently..
Tarbuck really doesnt suit our slick 1-2 passing style od play, for all the talent he has.... Arry did well to shift him along, and the player himself can now be a big fish in a much smaller pond...